JPS62293996A - Control of variable speed pumping-up power generation system and apparatus therefor - Google Patents

Abstract

PURPOSE:To permit high efficiency operation, by finding the value opening of a governor and the rotating speed of a generator to allow the optimum operation based on the lift or the head drop of the water and the power command value. CONSTITUTION:If a generator output target value Po and a static head H are given, then a command value calculation circuit 10 outputs the optimum rotating speed No of an induction generator 2 and the governor valve opening HV of a governor 8. Making a comparison between the optimum rotating No and the actual rotating speed N and between the target value Po and the actual output P by an effective power introducing section 14, and from their difference a phase angle calculation circuit 15 works out the phase angle delta of an exciting signal inputted to the secondary windings 3a-3c of the induction generator 2 and the corresponding output signal is sent to an exciting quantity setting section 17, which specifies proper output quantity in response to this output and controls the secondary excitation of the induction generator 2 through phase shift circuits 16a-16c. On the other hand, the governor valve opening output HV is sent to a value opening setter 11.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Application of the Invention] The present invention relates to a control method and a control device for a variable speed pumped storage power generation system, particularly a variable speed pumped storage power generation system that enables high efficiency operation during power generation and pumping. The present invention relates to a control method and a control device for a pumped storage power generation system.

[Background of the invention]

Pumped storage power generation is used in various places as a system to improve the overall operating efficiency of power supply systems, but in conventional pumped storage power generation systems, the load cannot be adjusted during pumping, and the amount of power generated during power generation and pumping operation is limited. The disadvantage is that the efficiency of the system changes depending on the pump head and head value, etc. However, in recent years, instead of the conventional pumped storage generator using a synchronous machine, a so-called variable speed pumped storage power generation system that uses an induction machine with a secondary excitation amount has been introduced. It has come to be widely used. Although this system has been developed, the method for determining optimal operation and the specific control method have not been clarified.

For example, 1981 IEEJ National Conference Paper & 553
describes this kind of system.

[Purpose of the invention]

An object of the present invention is to provide a control method and a control device for a variable speed pumped storage power generation system that can be operated with high efficiency in variable speed pumped storage power generation.

[Summary of the Invention] The control method for a variable speed pumped storage power generation system of the present invention connects a generator motor to a water turbine, and uses an induction motor that performs variable speed operation by changing secondary excitation in the generator motor. The pump-electric motor is operated, and during power generation, the water turbine-generator is operated to configure the pumping and power generation system, and the operation is performed by variable control of the opening of the governor valve that adjusts the rotation speed of the water turbine and the rotation speed of the induction machine. In a control method for a variable speed pumped storage power generation system,
The output command value of the generator is given to determine the opening command value of the speed governor valve and the speed command value of the generator, and the opening of the speed governor valve is controlled by the opening command value of the speed governor valve, and the opening command value of the speed governor valve is controlled by the opening command value of the speed governor valve. Find the difference between the speed command value and the actual speed, and the difference between the output command value of the generator and the actual generator output, and use these differences to determine the control phase angle of the generator secondary winding. The variable speed pumped storage power generation system control device of the present invention is characterized in that the amount of secondary excitation of the generator is controlled based on the calculated phase angle. The main motor is an induction machine with secondary excitation, a valve opening setting device for controlling the opening of the governor valve of the governor, a speed generator for detecting the rotational speed of the water turbine, and a speed generator for detecting the rotational speed of the water turbine. The induction machine includes a phase angle calculation unit that controls the secondary excitation phase, an excitation amount setting unit that determines the excitation t of the secondary excitation, and an active power derivation unit that calculates the output power of the induction machine. A control device for a variable speed hot water power generation system that performs variable speed control, characterized in that a command value calculation circuit is provided for calculating a valve opening command value of the speed governor and a speed command value of the induction machine. .

In other words, the present invention determines the valve opening of the governor and the rotational speed of the generator that enable optimal operation based on the head or head and the power command value during pumping and power generation operations, and calculates the The objective was to achieve efficient operation.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be explained based on the drawings. First, FIG. This section provides an overview of the variable speed power generation system and AFC control (automatic frequency control).

The diagram shows A of a three-phase induction generator (hereinafter referred to as an induction generator).
This is an explanatory diagram of the FC control circuit, and this generator is a secondary (rotor)
Variable speed can be obtained by changing the amount of excitation. 1 is a power system, 2 is an induction generator, and a stator 28. It has a rotor 3. 2a, 2b.

2C are the windings 3a and 3b of the stator 23, respectively.

3C indicates the excitation winding of the rotor 3, respectively. The rotor 3 is connected to a water wheel shaft, and the rotation speed is detected by a rotation speed measuring section 4. Reference numeral 5 denotes a frequency detection section, and reference numeral 6 denotes a voltage generation section that converts a detection signal of the frequency frequency into an excitation voltage.

In the figure, if the rated frequency is f and the slip is fts, the rotation speed of one rotor 3 is given by f(1-s), and the rotation speed of one rotor 3 is given by f(1-s).
By excitation at the frequency of the excitation winding 3at 3bt 3ce slip S, the rotating magnetic field generated in the rotor 3 becomes zero (synchronous speed) and becomes the same as the speed of the rotating magnetic field of the stator 2S. Is the frequency of the slip S the output of the rotation speed measuring section 4? The frequency is input to the frequency detection section 5, and is detected by comparing it with the rated frequency. The voltage generator 6 inputs the signal from the frequency detector 5 and generates excitation voltages corresponding to all nine frequencies to drive the excitation winding (secondary winding) 3 of the rotor 3.
Excite a, 3b, and 3c. In this way, by exciting the excitation winding of the rotor 3 at the frequency of Spell s, the windings 2a, 2b, 2C of the stator (armature) 28 are It is possible to always generate voltage at the grid frequency.

In other words, the rotating magnetic field of the rotor 30 is f (ls)-)-f -s=f...
... (1), so the output of induction generator 2 is
Regardless of the frequency, output at the rated frequency will be obtained.

The above is an overview of the variable speed power generation system using the induction generator 2 and the AFC operation, but the power generation system in this embodiment of the present invention takes into account the characteristics of the water turbine and adjusts the power generation system based on the head, head, power command value, etc. The system controls the opening/closing of the speed valve and the rotational speed of the generator at its maximum efficiency to achieve optimal operation during one pumped-storage power generation process, as will be explained below with reference to FIGS.

FIG. 1 shows a basic block diagram of an embodiment of a control device for a variable pumped storage power generation system according to the present invention.

In the figure, 1 is a power system, and 1a is a power transmission system.

2 is an induction generator; 26 and 3 indicate a stator and a rotor, respectively; 3a, 3b, and 3c are rotors 3;
The excitation windings of each phase of a, b, and c are shown.

Reference numeral 7 indicates a water wheel section, and 8 is a speed governor of the water wheel section 7, which has a valve opening adjustment mechanism. 9 is a speed generator.

The characteristics of the water turbine section 7 are determined by the static head (and the valve opening of the speed governor 8), and based on the characteristics, the rotor 3 of the induction generator 2 transmits the rotation. 10 is a command value calculation circuit , static head H and generator output command value P.

is given, the opening command value Hv and the speed command value Nok of the speed governor valve of the speed governor 8 are calculated in consideration of operational efficiency.

Reference numeral 11 denotes a valve opening setting device, which operates according to the opening command from the command value calculation circuit 10, and applies the governor valve opening command value 1 (Y? to the governor 8 via a time delay element to set the governor valve opening). Control the degree.12
is a current transformer, and 13 is a voltage transformer. Reference numeral 14 denotes an active power deriving section, which outputs O1l! from the current transformer 12 and the voltage transformer 13. Flow.

Input the voltage and calculate the active power lr. Reference numeral 15 denotes a phase angle calculation unit, which calculates the speed N generated by the speed generator 9 and the generator output command value P obtained from the command value calculation circuit 10.

, speed command value No., and the output of the active power deriving section 14 are input, and based on these various values t, the control phase angle f! of the excitation windings 3a, 3b, 3c of the rotor 3 of the induction generator 2 is determined. :calculate. 16a, 16b, l6c are phase shift circuits for voltages applied to the excitation windings 3a, 3b, 3c.

17 is an excitation amount setting section, which is an excitation winding 3a.

What is the amount of excitation applied to 3b and 3c? It is applied to the excitation windings 3a, 3b, 3C through the phase shift circuits 16a, 16b, 16c2. 18 is a voltage adjustment section,
The output voltage of the voltage transformer 13 is input, and the excitation amount setting section 17
This is to control the voltage value of the excitation amount.

In the control method and control device for the variable speed pumped storage power generation system of this embodiment, when the generator output command value or target value Pa and static head difference H required for the induction generator 2 are given, the command value calculation circuit lO These values are calculated and the optimal rotational speed NOI of the induction generator 2 and the governor valve opening degree Hv of the governor 8 are output. The phase angle calculation circuit 15 compares this output rotation speed No. with the actual rotation speed N determined by the output of the speed generator 9, and also compares the actual output P and target value Pa from the active power derivation section 14.
The difference between the secondary excitation windings 3a and 3b of the induction generator 2 is compared.
, 3c is calculated, and a corresponding output signal is sent to the excitation amount setting section 17. The excitation amount setting section 17 determines an appropriate amount of excitation according to this output, and sets the appropriate amount of excitation to the phase shift circuit 16a.

"1 '6 b, 16 C to control the secondary excitation of the induction generator 2. On the other hand, the governor valve opening output H
v is sent to the valve opening setting device 11 and converted into a valve opening signal, and this signal is sent to the speed governor 8 via a time delay element.
The opening degree of the speed regulating valve will be adjusted.

Here, the governor valve opening degree Hv and the generator rotational speed No are determined as follows.

Figure 2 shows the relationship between the combination of the water turbine rotation speed N and the governor valve opening Y for the maximum efficiency of the water turbine, and the generator output command value Po and head H? FIG. In the figure, the horizontal axis is the generator output command value PC1bMoki1! II indicates the lift height H.

As shown in the figure, for example, a generator output command value P.

are Pi and P, respectively, the combination of water turbine rotation speed N and governor valve opening Y is s Nt g Yl and Nz,
It becomes Y*. That is, when the generator output command value P6 and the head H are given, the governor valve opening Y and the rotation speed N corresponding to them can be obtained using FIG.

In this way, in the embodiment shown in FIG.
1 When the generator output command value Po is given, the target value HV% of the governor valve opening, the target value N0 of the generator rotation speed, is calculated, and the secondary excitation of the generator is controlled based on this target value. That will happen.

As mentioned above, using the characteristics shown in Fig. 2, the command value calculation circuit 10 calculates the rotation speed N and the governor valve opening Y, and then calculates the relationship between the rotation speed N, generator efficiency, and water turbine output. .

Here, the main part of FIG. 1 is extracted and shown in FIG. 3.

C in the figure is a control command section, and the command calculation circuit 1 in FIG.
0, the valve opening degree setting device 11, the phase angle calculation section 15, the excitation amount setting section 17, and the voltage adjustment section 18 are collectively represented, T indicates the operating end, and Ex indicates the excitation circuit.

When the output command value P0 of the induction power generation @2 is given from the operating end T, the governor valve opening Y2 and the rotation speed N are determined. .

However, in this case, the relationship between generator efficiency and rotational speed N is determined as shown in FIG. 4.

Figure 4 shows the relationship between the water turbine output, generator efficiency, and rotation speed, and a Francis turbine is used as the water turbine. The horizontal axis is the water turbine output Pw, the vertical axis is the generator efficiency 1 minute, and the rotation speed N.
is shown as a parameter.

The figure shows that the highest efficiency η2 is obtained at the rotation speed Ns in the output P1 at the rotation speed Ns, and the highest efficiency η2 is obtained at the rotation speed N2 in the output PI. As shown in the figure, the rotation speed N at which the efficiency η is the highest varies depending on the water turbine output Pw, but in this embodiment, the command value calculation circuit 1 shown in FIG.
By calculating the rotation speed N shown in FIG. 4 as the rotation speed command value No at 0, the generator can always be operated at the highest efficiency.

Next, secondary excitation of the rotor 3 of the induction generator 20 is performed by excitation using the slip frequency.

An output voltage of the rated frequency is generated at the output of the induction generator 2, and in this case, the secondary excitation windings 3a, 3b.

The excitation voltage applied to 3C is given as follows. That is, the phase angle Δa of the voltage applied to the excitation windings 3a, 3b, and 3c is calculated by the phase angle calculating section 15 when the power command value P is given, and the phase angle Δδ calculated by the phase angle calculating section 15 is A signal corresponding to the excitation voltage vf for the excitation windings 3a, 3b, 3c is input to the excitation amount setting section 17.

Vtbg'/I'a is determined. Each of these excitation voltages is given by (2). Here, E is a voltage value determined by the slip and operating conditions of the variable speed induction machine, δ0 is a phase angle determined by the operating conditions of the variable speed induction machine, and Δδ is a phase angle determined by the phase angle calculating section 15.

When controlling secondary excitation of induction generator 2 using equation (2), the voltage E (f- is used to control the reactive power, and the phase angle is used to control the active power. This means that control can be performed using Δδ.

The embodiment shown in FIG. 1 stably controls the active power during AFC operation using equation (2).

As described above, by using this embodiment, when the generator output command value Po and the static head H of the water turbine are given from the operating end T shown in FIG. The governor valve opening degree Hv of the water turbine governor and the generator rotation number No. that maximize the efficiency of the turbine are determined. Using these as target values, the governor valve opening setting value and the generator secondary excitation are determined. A control method and a control device for a variable hot water power generation system with high operational efficiency and stability by controlling the amount, determining the optimum governor valve opening and rotation speed, and performing AFC control.
can be obtained, and the economic effect on the power system is extremely large.

〔Effect of the invention〕

According to the present invention, it is possible to provide a control method and a control device for a variable speed pumped storage power generation system that can be operated with high efficiency.

[Brief explanation of drawings]

Figure 3g1 is a block diagram of an embodiment of the control device for a variable speed pumped storage power generation system of the present invention, and Figures W and 2 are output command values. An explanatory diagram showing the relationship between pumping head, water turbine rotation speed, and governor valve opening degree, Fig. 3 is a block diagram of the main part of Fig. 1, and Fig. 4 is an explanation showing the relationship between water turbine output 1 generator efficiency and water turbine rotation speed. FIG. 5 is a schematic diagram of a variable speed power generation system. l...Power system, 2...Induction generator, 7...Water wheel section, 8...Speed governor, 9...Speed generator, 10...
Command value calculation circuit, 11... Valve opening setting device, 14...
Active power calculation unit, 15... Phase angle calculation unit, 16...
Phase shift circuit, 17... Excitation amount setting section, 18... Voltage adjustment section. 2nd prisoner 4- eyes

Claims (1)

[Scope of Claims] 1. A generator-motor is connected to the water turbine, and the generator-motor is equipped with an induction motor that performs variable speed operation by changing secondary excitation. When pumping water, the pump-motor operates, and when generating water, the water turbine-motor operates. A control method for a variable speed pumped storage power generation system, which configures a pumped storage and power generation system as a generator operation, and operates the variable speed pumped storage power generation system by variably controlling the opening degree of a governor valve that adjusts the rotational speed of the water turbine and the rotational speed of the induction machine. In the step, an output command value of the generator is given to obtain an opening command value of the speed governor valve and a speed command value of the generator, and the opening of the speed governor valve is controlled by the opening command value of the speed governor valve. Find the difference between the speed command value of the generator and the actual speed, and the difference between the output command value of the generator and the actual generator output, and calculate the control phase angle of the generator secondary winding from these differences. and controlling the amount of secondary excitation of the generator based on the calculated phase angle. 2. A water turbine, a water turbine speed governor, and a secondary excitation induction machine connected to and driven by the water turbine as main engines, a valve opening degree setting device for controlling the opening degree of a speed governor valve of the speed governor, and the water turbine; a speed generator that detects the rotational speed of the induction machine; a phase angle calculation unit that controls the secondary excitation phase of the induction machine; an excitation amount setting unit that determines the amount of excitation of the secondary excitation; In the control device for a variable speed pumped storage power generation system, the control device includes an active power derivation unit that calculates an active power derivation unit, and controls the induction machine at variable speed. 1. A control device for a variable speed pumped storage power generation system, comprising a command value calculation circuit.