JPS5910200A - Starting method and starter for motor - Google Patents

Abstract

PURPOSE:To eliminate the rise of the output power of a generator over the rated output by feeding back the current flowed to a motor and the power which is inputted to the motor to an automatic voltage regulator of the generator. CONSTITUTION:An automatic voltage regulator 12 controls to fire a thyristor 9 so that the deviation between the output voltage and the reference voltage of a generator 2 becomes small, thereby maintaining the output voltage of the generator 2 constant. On the other hand, the current which is flowed to the motor 6 which is detected by a current transformer 14 is inputted to the regulator 12 through a current setting variable resistor 16 and the input power amount of the motor 6 detected by a power amount converter 18 is inputted to the regulator 12 through a power setting variable resistor 19, thereby regulating so that the current inputted to the motor 6 does not flow more than the prescribed value and the power amount inputted to the motor 6 does not become more than the prescribed value. In this manner, the stoppage of a prime mover can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved method for starting a motor with a large starting capacity using a generator.

Generally speaking, a ship is equipped with multiple engines for safety reasons. These generators are always operated in parallel to supply power at the rated voltage and frequency to the power supply bus inside the ship. Incidentally, a ship is sometimes equipped with a squirrel-cage conductive motor having a large starting capacity, such as a bow thruster. If a motor with such a large starting capacity is connected to the ship's busbar for direct starting, the voltage and frequency of the power supply bus may drop due to the electromotive current, which may have an adverse effect on the ship. 0 Therefore, when starting such a large frost 1 motor with a large starting capacity, a parallel operation state (- one of the multiple generators is disconnected and the output voltage of only that one generator is brought to zero) is used. After that, the generator is electrically connected to the motor to be started, and the output voltage of the generator is gradually increased while suppressing the current flowing through the motor to start the motor. , a startup method has been proposed that does not cause a voltage drop or frequency drop on the power supply bus C inside a ship.0 However, this startup method does not cause a voltage drop or frequency drop on the power supply bus to which the generator is connected. (
-The electric motor can be started, but the following problems remain. In other words, in this starting method, the output voltage of the generator is adjusted while suppressing only the current flowing to the motor, but in order to increase the starting torque at low voltage and shorten the starting time, The maximum current flowing through the pump is suppressed to about 300 to 500% of the rated current value. For this reason, when the electric motor approaches its maximum rotational speed l2 and the power factor suddenly improves, the output power of the generator suddenly increases and may exceed the rated output of the generator. This rapid increase in the output power of the generator may cause a sudden loss of torque in the prime mover driving the generator, causing the prime mover to stop.

The object of the present invention is to reduce the amount of frost flowing into the electric motor at the rated current.

To provide a method for starting a motor that does not cause the output power of a generator to exceed the rated output and does not stop a prime mover even when the motor is started while flowing about 300 to 500% of sushi.

The present invention starts an electric motor using the output of a generator, in which the current flowing through the motor and the amount of electric power input to the motor are fed back to the automatic voltage regulator of the generator. Second, the present invention relates to a method for starting a motor, characterized in that the motor is started by gradually increasing the output voltage of the generator while suppressing the current flowing through the motor and the amount of electric power below a predetermined value.

The starting circuit diagram shown in FIG. 1 (FIG. 2) for carrying out the starting method of the present invention will be described below with reference to FIGS.

2 is a generator driven by the prime mover 1, and on its output side, a power supply mother 1w5 is connected via a switch 3, and a switch 4
A started motor 6 such as a squirrel-cage induction motor with a large starting capacity is connected through the motor.

In addition, the power supply bus 5 is not shown in the figure, but other power generation,
Power is always supplied from the device at the rated voltage and frequency.

Currents corresponding to the output voltage and output current of the generator 2 are taken out, respectively, and passed through the thyristor 9 to the field winding #i! of the generator 2. 10 is an accelerator and a current transformer, and 11 is a field switch that shorts both ends of the field winding 10 to reduce the output of the generator 2 to zero.

Reference numeral 12 indicates an automatic controller that compares the output voltage of the generator 2 obtained via the transformer 13 with a reference voltage, and controls firing of the thyristor 9 to keep the output voltage of the generator 2 constant so that the deviation is small. A voltage regulator, 14 is a current transformer that detects the current flowing to the motor 6, 16 is a variable resistor for current setting, and the current taken out in this way is fed back to the automatic voltage regulator 12, and the current flowing to the motor 6 is started. It is configured to suppress the current.

A known power converter that manually converts the voltage detected by the 8th transformer 13 (2) and the current detected by the current transformer 14 and outputs a signal according to the input power of the motor 6. This output signal is transmitted via the power setting variable resistor 19 to the automatic voltage regulator 12+two-person power 1~.

Therefore, in general, in addition to automatic heavy pressure adjustment, this automatic voltage regulator 12 prevents the TK flow flowing to the motor 6 from exceeding a predetermined value, and furthermore, the electric power and power input to the motor 6 do not exceed a predetermined value. It also performs similar adjustment actions.

The circuit of the automatic voltage regulator 12 is constructed as shown in FIG. 1. In other words, how can it be broadly classified? Voltage control circuit 50. Constant power control circuit 51 and constant 'Fl'l m.

It is composed of a control circuit 52. The constant voltage 1t control circuit 50 is detected via the transformer 13)1. The first rectifier circuit 20 rectifies the output voltage of the generator 2, and the output voltage of the generator 2 rectified by the rectifier circuit 20 is equal to
The deviation is compared with the set voltage set by the pressure setting device 21, and the pressure is amplified by the first amplifier 22α. or third rectifier 2
3d 124Q, 25a and the first and second resistors 26.
27α and a transistor 28α.
9 is amplified and output to the phase control circuit 30, and the circuit is configured so that the thyristor 9 is controlled by a pulse signal corresponding to this deviation voltage. Therefore, the output voltage of the generator 2 is controlled by the voltage setting device 21 by this constant voltage control circuit 50.
A field current is passed through the field winding lO of the generator 2 so that the voltage and voltage correspond to the set Mt pressure.

The switched constant power control circuit 51 outputs the output voltage of the generator detected via the transformer 13 and the input voltage D1 of the motor 6 detected via the current transformer 14. A converter 1 that outputs a voltage according to the amount of electric power input to the power supply machine 6 from the power source 6.
8, and the converter j8 converts I]-l motor 6
The input type, force Ni: ld, is compared with the setting voltage and pressure set in the power equipment redundant device 19, and the deviation voltage is the second increase [
The IJ device 22 is incremented by the 1st, then the 4th to 6th.
The amplitude is increased [1] by a second amplifier circuit 296 consisting of rectifiers 23h, 24J, 254 and first and third resistor (j, 274.) transistors 284, and the phase is controlled by 1jj.
l path, 301 - output il, which is converted by this circuit 30 to the thyristor 9 by a pulse signal corresponding to the polarized voltage g2.
It is said that the C two-circuit Yang Cheng is in charge of the system. In this constant plane, the output frost of the generator 2, by the force 11il control circuit 51,
The power setting device 19 inputs and outputs the electric motor 6.
The setting device sets the field type of the field winding of the generator 2 to produce electric power according to the pressure, and the current is set to r'.

The constant current control circuit 52 includes a second V-wave circuit 15 that rectifies a voltage corresponding to the output current of the generator 2 detected via the current transformer 14, that is, the input current of the electric motor 6,
The input current of the motor 6 obtained by this rectifier circuit 15 is
The voltage deviation is compared with the set voltage set by the current setting device 16, and the deviation voltage is amplified by the third amplifier 22r. Fourth resistor z6.27C and transistor 28
The thyristor 9 is controlled by a pulse signal corresponding to the deviation voltage outputted from the phase control circuit 30. The circuit is configured as follows. This constant current control circuit 52 adjusts the output current of the generator 2, that is, the input 1 to 3 current of the motor 6, to the current for the field winding of the generator 2, depending on the set voltage of the current setting device 16. A field current will flow.

However, (7) the first amplification circuit 29a of the constant voltage control circuit 50, the second amplification circuit 296 of the constant power control circuit 51, and the third amplification circuit 29C of the constant current control circuit 52 are phase controlled. Circuit; Since a logical sum circuit, a so-called OR circuit, is configured for 30, each transistor in each circuit has a ratio of 28.7%2
i, the lowest emitter voltage of 28C is the phase control circuit 30
Enter C. Therefore, the output voltage of the generator 2 is small, and the output current of the generator 2, that is, the voltage I) li<4
6, the field winding 10 of the generator 2 is rated and controlled by the current circuit 29C. Sword motor 6
The input current is small, and the output power of 1 machine 2 is electric +1! :6, the field winding 10 of the generator 2 is controlled by the constant power circuit 298.

In addition, in FIG. 2, 3Ct3i and 31C are the first and
The second and third advance circuits each include a first rectifier circuit 20, a frost,
In order to detect the rising slope of the output voltage of the force converter 18 and the second #current device 15 and improve the transient response, a phase lead circuit 32 is divided into two parts, and 32 is a hook, and by passing the set voltage of the release setting device 10. This is a ramp function circuit that slows down the rise of the input current to the motor 60. Phase advance circuits 314, 31
4.31C and ramp function circuit 32-1 may be omitted depending on the city, motive characteristics, and generator characteristics.33
d, 3. In, 33CH each lti, 1st, 2nd, 3rd
This is a circuit for adjusting the amplification rate and preventing disturbance between the input and output of the amplifiers 22a, 22-6, and 22C.

Next, as described above, 1: Configuration, 1 (+1 yen B, 1st explanation of how to start the electric motor 6 using the pressure conditioning device 12)
This will be explained with reference to FIGS. 2 and 3. First, when starting the electric motor 6, since υ, the output voltage, output current, output lightning, and power of the generator 7 and the generator 2 are zero, the first and second
The outputs of the rectifier circuit 2 (+, 15 and the power f1 converter 18 are zero. Therefore, the first, second and third amplifiers 2
The deviation type H operated by two people 2a, 22k, and 22C1 is also maximized, and the phase control circuit 30 outputs a pulse signal to cause a large box flow to flow to the field winding.

In this state, when the field switch 11 installed in parallel with the field winding 10 is opened, the output of the generator 20 decreases by % due to the residual voltage of the generator 2 and the above-mentioned action 52. As shown in the machine's output voltage characteristic A, g2 rises and the electric power! ! The III machine 6 starts to start up. When the electric motor 6 is started in this way, the starting current suddenly increases as shown in 1 in FIG. l'
I'? ! % 22'l The deviation pressure exerted by two people suddenly decreases, and a voltage corresponding to this deviation pressure is input to the 1-phase control circuit 30. That is, at this stage, the control functions of the constant voltage control circuit 50 and the constant power control circuit 51 are suppressed, and the constant current control 1r11 path 52 takes priority.

This rated and AL control function of the light control circuit 52 continues until the rotation of the electric motor 6 approaches the rated rotation and the starting current suddenly decreases, and the current and current input to the electric motor 6 are controlled by the current setting device 10. The current is suppressed according to the set voltage. In this way, the current is suppressed] 1. When the 6-piece electric motor starts up and its rotation approaches the rated rotation speed ζ1, the 3rd and 1st 1: At the time of human power ↑'(: As shown in C, the power of lightning suddenly becomes stronger, so the deviation voltage input to the second amplifier 226 suddenly becomes f21J-IJ< This means that the pressure is input according to the individual pressure.In other words, at this stage, the control functions of the constant voltage control circuit 50 and the rating and light control circuits 52 are suppressed, and the constant power control circuit 51 takes priority. I will do it.

The control function of this constant voltage and force control circuit 51 is the wattmeter setting!
! The electric power input to the electric motor 6 is suppressed to the electric power amount corresponding to the set voltage of the electric power envy setting gain 19 by increasing the electric power amount until it becomes lower than the electric power meter corresponding to the design voltage of '-1. Like this C2(,te'
The current flowing to the motor 6, the box, and the power are set by the current setting device 16.
and 'FM according to the setting voltage set of the electric energy setting device 19,
The motor 6 is started by increasing the output voltage of the generator 2 while suppressing the current and electric power.

Next, when the rotation speed of the electric motor 6 reaches the rated rotation speed (1),
Since the 1h'1 force input to the maneuver @6 suddenly becomes slightly distorted, the constant voltage control circuit 50 changes to the constant current and force control circuit 5.
1 and 10 control functions of the foot current control circuit 52. In this way, the electric motor 6 reaches the rated rotation speed i twice, and is controlled by the constant voltage control circuit 50.
@2 output point; pressure is constant (1 is maintained.

Figure 3 shows the output voltage characteristics A of the generator 2 and the electric motor 6 when the electric motor 6 is started using the automatic voltage regulator 2.
This is an example showing the input current characteristic B of the motor 6, the human power characteristic C of the electric motor 6, and the torque characteristic of the electric motor 6. As can be understood, it is necessary to suppress the current flowing through the motor 6 to the rated current, which is about 300 to 500, and to start the motor 6 while suppressing the electric power input to the motor 60 to the rated output of the generator 2. As a result, even if the electric motor 6 approaches the rated rotation speed (2) and the power factor suddenly improves, the output of the starter 2 will not suddenly increase (2) and the motor 1 will not stop.

Another embodiment shown in FIG. 4 is the electric power in the embodiment shown in FIG. Apparent cal converter 3 instead of tL converter 18
・It uses 1. According to this, it is possible to set the maximum amount of allowable apparent power output from the generator 2, so
If the setting power field is set to a value (1-1) that can be tolerated by the generator 2, it is possible to not only prevent the prime mover 1 from stopping, but also to prevent the generator 2 itself from burning out.

As described above, according to the starting method (2) of the present invention, when starting the electric motor using the output of the generator in a rotating state, Generator cloth while suppressing two.

Since the pressure is gradually increased to start the generator, even if the motor approaches its rated rotational speed and the power ratio improves, it is possible to prevent the motor from stopping without exceeding the generator's rated output. Furthermore, suppressing the apparent power amount to a predetermined value or less has the effect of preventing burnout of the generator. Furthermore, when used in rated operating conditions, it can operate within a specified apparent power amount, protect against generator overcurrent due to grid voltage fluctuations that occur during parallel operation with the grid, and prevent loads from short-circuiting. (Even the 7th one has the effect of keeping the flow flowing.

[Brief explanation of the drawing]

Fig. 1 is a starting circuit diagram for explaining the method of starting a motor according to the present invention C, Fig. 2 is a circuit diagram showing an embodiment of the self-shaft voltage regulating device used in the present invention, and Fig. 3 is a circuit diagram of the present invention. C1 is a characteristic diagram of the electric motor and the electric motor used, and FIG. 4 is a circuit diagram showing another embodiment of the automatic voltage regulator used in the present invention. 1... Original iJJ machine 2... Generator 5...
Power supply bus 6...Enclosed ring 1] Motor 7...Reactor 8...Current transformer 9...Thyristor I
O...Field winding 11...Field switch 12...
・Automatic voltage regulator 13...Transformer 14・
... Current transformer 15 ... Rectifier 16 ... Variable resistor 18 ... Power converter 20 ... Rectifier circuit 22a, 22J, 22c - ... Amplifier procedure amendment (self-proposed) 6゜December 20, 1981 Mr. Commissioner of the Japan Patent Office 1 Indication of the case Patent Application No. 115606/1983 2 Name of the invention Method for starting an electric motor and its starting device 3 Relationship with the amended person case Patent applicant and me Nishishiba Electric Co., Ltd. 4 Agent 5, Toranomon, Minato-ku, Tokyo 105, Minato Densetsu Building, Inomata Patent Office, 9-10 Chome Subject of amendment 1 Detailed explanation of the invention in the specification Contents of amendment 1 Specification of the application On page 3, line 19 of the book, add the seven characters ``and starting device'' next to ``method''. 2 In the same specification, W, page 4, line 7, “the electromotive current” is replaced with “
``The starting current'' is corrected. 3.11[]1'@°1″. “tllrt] [il! 4
29J l. is corrected as "width amplifying circuit 29a." 4. [......] on page 12, line 2 of the same specification
2, insert the following statement next to "Open the switch 3 to disconnect the generator 2 from the power supply bus 5.Then, close the field switch 11 to disconnect the output voltage of the generator 2. After setting it to zero, close the switch 4 and electrically connect the motor 6 and generator 2.

Claims (1)

[Scope of Claims] (1) In a method for starting an electric motor by the output of a generator controlled by a voltage regulator, the current and power phase input to the electric generator are controlled by the generator'@,
Automatic voltage regulator 52 feedback (2) This automatic voltage regulator gradually increases the output voltage of the generator while suppressing the current and power input to the motor to below a predetermined value. (2) The automatic pressure regulating device has a constant current control circuit, a constant power control circuit, and a constant voltage control circuit, and the rated rotation is maintained from the beginning of starting the motor. When the number approaches the starting frost and the flow suddenly decreases, the constant current control circuit suppresses the current input to the motor below a predetermined value while gradually increasing the output voltage of the generator, until the motor's rotational speed reaches the rated speed. When the number of revolutions approaches and the amount of power input to the motor increases, the input angle and power become less than a predetermined value.At 1, the constant power control circuit controls the amount of power input to the motor to a value less than a predetermined value, and the generator is activated. output phase, gradually increasing the pressure,
The town according to claim 1, characterized in that when the rotational speed of the electric motor reaches the rated rotational speed, the constant voltage control circuit performs control so that the output voltage of the power generation station becomes constant C2. , Method for starting a motor (8) In a device for starting a motor by the output of a generator controlled by an automatic voltage regulator, the automatic voltage regulator compares a set voltage of a voltage setting device with an output voltage of the generator. and a constant voltage control circuit that controls the output type and voltage of the generator to a voltage according to the set voltage C of the voltage setter, and compares the set voltage of the current setter and the current flowing through the motor C1 to determine the voltage of the motor i1. a constant current control circuit that suppresses voltage control of the constant voltage circuit in order to suppress the flowing current to a current that corresponds to the current setting of the current setting device; and a setting voltage of the electric energy setting device and electric power input to the electric motor. Compare (7) a constant power control circuit that suppresses voltage control of the constant power output circuit in order to suppress the amount of power input to the front power distribution motor to the amount of power that corresponds to the set voltage in of the power amount setting device. (4) A starting device for a motor, characterized in that the device is configured to compare the set voltage of the current setting device of the constant current control circuit in the automatic voltage regulator with the current flowing to the motor through the ramp function circuit. (6) A constant voltage control circuit in an automatic voltage regulator,
In the constant current control circuit and the constant power control circuit, if the output voltage of the generator and the current flowing to the motor are 1 - the voltage corresponding to the amount of power input to the motor is advanced through the circuit and set by the respective voltage setting device and lightning, passing setting. Compare the set voltages of the power setting device and power amount setting device (
The starting device for an electric motor according to claim 3, characterized in that it has two configurations.