JPH04200300A - Operation control method of pumping-up power generating system - Google Patents

Abstract

PURPOSE:To start-up the terminal voltage of a generator motor to a given voltage efficiently by a method wherein the starting of a main engine and the initial exciting upon excitation are effected employing an initial charging circuit belonging to a sine wave PWM control inverter converter under a condition that an internal power supply is not taken from a transmission line. CONSTITUTION:When a generator motor 1 is started and the rotating speed of the same has arrived at a given speed, GTO1 and GTO2 or GTO3 and GTO4 are put ON whereby an initial DC exciting current is supplied to the generator motor 1. The terminal voltage of the generator motor 1 is risen up by the initial exciting while the voltage increases the voltage of a DC link capacitor 3 through a power supply transformer 5 and a three-phase fullwave rectifying circuit constituted of the diode 4b of a converter 4. After rising the terminal voltage of the generator motor 1 to a given voltage by these one series of automatic operations, the control of the inverter 2 and the converter 4 is switched to an ordinary sine wave PWM control to effect the constant control of the terminal voltage and frequency of the generator motor 1 and the voltage of the DC link capacitor 3.

Description

[Detailed Description of the Invention] [Purpose of the Invention (Industrial Application Field) The present invention relates to a method for controlling the operation of a pumped storage power generation system of AC secondary excitation type using a sine wave PWM control inverter/converter converter. .

(Prior Art) FIG. 4 is a diagram showing an example of a circuit configuration of an AC secondary excitation type pumped storage power generation system using this type of sine wave PWM control inverter/converter converter. In FIG. 4, the pumped storage power generation system includes a generator motor 1, an inverter 2,
It is composed of a DC link capacitor 3, a converter 4, a power transformer 5, an initial excitation circuit 6, a changeover switch 7, a parallel breaker 8, and a line-side breaker 9.

Here, the generator motor 1 has a wound rotor 1a and a stator 1b, and the stator 1b is connected to a power transmission line (not shown) via a parallel breaker 8 and a line-side breaker 9. has been done. Furthermore, the inverter 2 supplies a variable frequency alternating current voltage to the rotor 1a of the generator motor 1. Furthermore, the DC link capacitor 3 serves as a DC power source for the inverter 2.

On the other hand, the converter 4 supplies DC voltage to the DC link capacitor 3. Further, power transformer 5 supplies alternating current voltage to converter 4 . moreover,
The initial excitation circuit 6 activates the generator motor 1 at the time of black start.
This is for initial excitation. Furthermore, the changeover switch 7 is used to switch between connecting the rotor 1a of the generator motor 1 to the inverter 2 or to the initial excitation circuit 6.

Now, in such a pumped storage power generation system, when starting 1 excitation (hereinafter referred to as black start) of the main engine is performed in a state where the station power source cannot be obtained from the power transmission line (for example, when the power transmission line is without voltage). In this case, with the parallel circuit breaker 8 closed and the track side circuit breaker 9 open,
The initial excitation circuit 6 is switched to the generator motor 1 by the changeover switch 7.
is connected to the rotor 1a. As a result, after the generator motor 1 starts and reaches a constant rotational speed, initial excitation is applied to the generator motor 1 from the initial excitation circuit 6 to raise the stator voltage (hereinafter referred to as terminal voltage) of the generator motor 1. increase.

On the other hand, as shown in FIG. 5, the converter 4 is composed of an anti-parallel circuit of a GTo element 4a and a diode 4b, but since the diode 4b constitutes a three-phase full-wave rectifier circuit,
As the terminal voltage of the generator motor 1 increases, the AC voltage supplied from the power transformer 5 is converted into a DC voltage by the three-phase full-wave rectifier circuit. When this DC voltage becomes higher than the voltage of the DC link capacitor 3, charging of the DC link capacitor 3 starts, and the DC link capacitor 3 starts charging.
increase the voltage. As a result, after the voltage of the DC link capacitor 3 reaches a certain voltage, the changeover switch 7 is switched to connect the inverter 2 to the rotor 1a of the generator motor 1, and the inverter 2 and converter 4 are utilized to generate normal sine wave PWM. The terminal voltage and frequency of the generator motor 1 and the voltage of the DC link capacitor 3 are controlled to be constant.

However, in the above-described operation control method, when performing a black start, the dedicated initial excitation circuit 6 for the black start, the rotor 1a of the generator motor 1,
It is necessary to use a changeover switch 7 for switching the connection of the inverter 2 and the initial excitation circuit 6, which not only complicates the overall system configuration but also increases cost.

(Problems to be Solved by the Invention) As described above, in the conventional operation control method of a pumped storage power generation system, when performing a black start, it is necessary to use a dedicated initial excitation circuit and a changeover switch for the black start. There was a problem.

An object of the present invention is to efficiently raise the terminal voltage of the generator motor to a constant voltage when performing a black start without using a dedicated initial excitation circuit or a changeover switch for the black start. An object of the present invention is to provide an operation control method for a pumped storage power generation system that can simplify the system configuration and improve economic efficiency.

[Structure of the Invention (Means for Solving the Problems)] In order to achieve the above object, the present invention provides a generator motor having a wound rotor and a stator, and an initial charging circuit that controls the rotation of the generator motor. In a method for controlling the operation of a pumped storage power generation system consisting of a sine wave PWM control inverter/converter converter that supplies a variable frequency AC voltage to a power generator, starting the main engine in a state where the on-site power source cannot be obtained from the power transmission line,
When excitation is performed, the DC link capacitor connected between the inverter and the converter is charged in advance by an initial charging circuit, and the energy charged in the DC link capacitor is supplied to the rotor of the generator motor via the inverter. Initial excitation is performed, and the voltage generated in the stator of the generator motor by the initial excitation is foot-hacked into the converter to increase the voltage of the DC link capacitor, and excitation is continued via the inverter, resulting in a series of self-excitation effects. The stator voltage of the generator motor is raised to a constant voltage.

(Function) Therefore, in the operation side control method of the pumped storage power generation system according to the present invention, it is necessary to start the main engine in a state where the in-house power source cannot be obtained from the power transmission line, to use the initial excitation during excitation, or to use the sine wave PWM control inverter/converter converter. By using the initial charging circuit attached to the unit, it is possible to efficiently raise the terminal voltage of the generator motor to a constant voltage while eliminating the need for a dedicated initial excitation circuit or changeover switch for black start. can.

(Example) First, when the sine wave PWM control inverter/converter converter is powered on from the grid and starts operation, in order to prevent rush current from the converter to the DC link capacitor, An initial charging circuit is included to pre-charge the link capacitor to a certain voltage.

Therefore, in the present invention, this initial charging circuit is used to perform initial excitation at the time of black start, and the terminal voltage of the generator motor is raised to a constant voltage by self-excitation of the generator motor.

Hereinafter, an embodiment of the present invention based on the above concept will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing an example of the circuit configuration of an AC secondary excitation type pumped storage power generation system according to the present invention using an initial charging circuit or an attached sine wave PWM control inverter/converter converter, and FIG. The same parts are given the same reference numerals and the explanation thereof will be omitted, and only the different parts will be described here.

That is, FIG. 1 omits the initial excitation circuit 6 and changeover switch 7 in FIG. 4, and shows the rotor 1 of the generator motor 1.
A is directly connected to the inverter 2. In addition, 1
0 indicates the initial charging circuit attached to the sine wave pwhx controlled inverter/converter converter.

Next, a method for controlling the operation of the pumped storage power generation system configured as described above will be explained with reference to FIGS. 2 and 3.

In FIG. 1, when performing a black start now, the parallel circuit breaker 8 is closed, the line-side circuit breaker 9 is opened, and the DC link capacitor is charged in advance by the initial charging circuit 10 for initial excitation. Charge 3,
Start up the generator motor 1 to a voltage that allows self-excitation.

Next, when the generator motor starts and reaches a constant rotational speed, the GTO elements GT○1 and GTO2, or GTO3 and GT
By turning on ○4, a DC initial excitation current is supplied to the generator motor 1.

This initial excitation causes the terminal voltage of the generator motor 1 to rise, and that voltage is applied to the voltage across the DC link capacitor 3 via the power transformer 5 and the three-phase full-wave rectifier circuit composed of the diode 4b of the converter 4. to rise. After the terminal voltage of the generator motor 1 is raised to a constant voltage by a series of self-excitation effects, the inverter 2 and the converter 4 are switched to normal sine wave PWM control, and the terminal voltage of the generator motor 1, frequency, and The voltage of the DC link capacitor 3 is controlled to be constant.

In this case, the control of the inverter 2 from switching to sine wave PWM control to shifting to constant terminal voltage control is as follows. For example, as shown in the control block diagram in FIG. 3, the terminal voltage ■1 of the generator motor 1 and the terminal voltage target value ■
Inverter output current command value 1 obtained from the deviation from 1'
8 and the inverter output current value i, an inverter output voltage command value v28 is obtained, and the terminal voltage of the generator motor 1 is controlled to a constant voltage by performing PWM control on the inverter 2 based on this. In addition, in FIG. 3, G1 is a voltage/current conversion transfer function for converting voltage into current, G
3 shows current/voltage conversion transfer functions for converting current into voltage.

As described above, in this embodiment, a generator motor 1 having a wound rotor 1a and a stator 1b, and an initial charging circuit 10 are used.
When performing a black start of a pumped storage power generation system consisting of a sine wave PWM control inverter 2 and a converter 4 that supplies a variable frequency AC voltage to the rotor 1a of the generator motor 1, the inverter 2 and converter 4 The initial charging circuit 10 pre-charges the DC link capacitor 3 connected between the Excitation is performed, and the voltage generated in the stator 1b of the generator motor 1 due to initial excitation is fed back to the converter 4 to increase the voltage of the DC link capacitor 3. Excitation is continued via the inverter 2, and a series of automatic The terminal voltage of the generator motor 1 is raised to a constant voltage by excitation.

Therefore, either the initial excitation at black start or the sine wave PW
Since the initial charging circuit 10 attached to the M-controlled inverter 2/converter 4 converter is used (), it is possible to generate power while eliminating the need for a dedicated initial excitation circuit or changeover switch for a conventional black start. It is possible to efficiently raise the terminal voltage of the motor 1 to a constant voltage.Also, since there is no need for a dedicated initial excitation circuit or changeover switch for black start, the configuration of the entire system is simplified accordingly. It will be possible to improve the efficiency and economic efficiency.

[Effects of the Invention] As explained above, according to the present invention, initial excitation at the time of black start is performed using the initial charging circuit attached to the sine wave PWM control inverter/converter converter. When performing a black start, the terminal voltage of the generator motor can be efficiently raised to a constant voltage without using a dedicated initial excitation circuit or changeover switch for black start, which simplifies the system configuration. A method for controlling the operation of a pumped storage power generation system that can improve economic efficiency can be provided.

[Brief explanation of the drawing]

Fig. 1 is a circuit configuration diagram showing an embodiment of an AC secondary excitation type pumped storage power generation system according to the present invention using a sine wave PWM control inverter converter attached with an initial charging circuit, and Fig. 2 is the same. A circuit diagram showing an example of the configuration of an inverter in the embodiment, Fig. 3 is a block diagram for explaining inverter control during initial excitation in the embodiment, and Fig. 4 shows a circuit diagram using a sine wave PWM control inverter/converter converter. A circuit diagram showing a configuration example of a conventional AC secondary excitation pumped storage power generation system,
FIG. 5 is a circuit diagram showing an example of the configuration of the converter in FIG. 4. 1... Generator motor, 2... Inverter, 3... DC link capacitor, 4... Converter, 5... Power transformer, 8... Parallel breaker, 9... Line side Breaker, 10... Initial charging circuit. Applicant's agent Patent attorney Takehiko Suzue Figure 1 - 11111112 Figure 2 Figure 4 4a 4b '4

Claims (1)

[Claims] A pumped storage system consisting of a generator motor having a wound rotor and stator, and a sine wave PWM controlled inverter converter having an initial charging circuit and supplying a variable frequency AC voltage to the rotor of the generator motor. In an operation control method for a power generation system, when starting and exciting a main engine in a state where in-station power cannot be obtained from a power transmission line, a DC link capacitor connected between the inverter and the converter is charged in advance by the initial charging circuit. , the energy charged in the DC link capacitor is supplied to the rotor of the generator motor via the inverter to perform initial excitation, and the voltage generated in the stator of the generator motor by the initial excitation is transferred to the rotor of the generator motor. increasing the voltage of the DC link capacitor by feeding back to and continuing excitation via the inverter;
An operation control method for a pumped storage power generation system, characterized in that the stator voltage of the generator motor is raised to a constant voltage by the series of self-excitation effects.