Digital excitation system control circuit of generator

Abstract

The utility model discloses a digital excitation system control circuit of a generator, which comprises an AVR voltage regulator, a permanent magnet generator power source and a stator winding, the permanent magnet generator power source is connected with the AVR voltage regulator and is used for providing a working power supply for the AVR voltage regulator, the stator winding comprises a U phase, a V phase and a W phase, the neutral point sides of the U phase, the V phase and the W phase are respectively provided with a U phase differential current transformer, a V phase differential current transformer and a W phase differential current transformer, and the V phase differential current transformer is integrated with a coil used for detecting the current of the generator. The permanent magnet generator is independent of the whole generator system, is not influenced by the whole power supply system, and is more stable and efficient as an automatic voltage regulator power supply, a group of coils is integrated on the V-phase differential current transformer for detecting the current of the generator, and the shape of the V-phase differential current transformer is kept unchanged. The increased coil cost is far lower than that of an original difference-adjusting current transformer, the limited space in the generator is saved, and meanwhile the working time cost is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of digital excitation system control circuit of generator. BACKGROUND

[0002] The excitation control mode of generator mainly has traditional analog excitation and new digital excitation, and digital excitation system has been widely applied in the field of generator due to its excellent dynamic performance, ability of carrying nonlinear load, perfect function and anti-harmonic ability, and digital excitation system mainly includes power source, current transformer, voltage transformer, AVR.Power source provides power supply for AVR, and the current transformer installed in V phase detects generator current, which is used to calculate generator load and realize the function of difference adjustment to finally meet the demand of generator parallel operation;Voltage transformer is used for AVR to detect voltage, and the stability of generator output voltage is adjusted through the internal PID operation of AVR.At the same time, in order to realize the internal protection of generator, three differential current transformers are installed in U, V and W neutral point sides.

[0003] At present, at least four current transformers are needed for the digital excitation system of one generator, which occupies a large space in the generator and has high cost, and the power source of AVR is taken from the output voltage of generator, which is easily affected by the load condition of generator itself and harmonic. UTILITY MODEL CONTENTS

[0004] The utility model aims at providing a kind of digital excitation system control circuit of generator to solve the problems raised in the above background technology.

[0005] To achieve the above purpose, the utility model provides the following technical scheme: a kind of digital excitation system control circuit of generator, including AVR voltage regulator, permanent magnet machine power source and stator winding, the permanent magnet machine power source is connected with AVR voltage regulator, to provide working power supply for it, the stator winding includes U phase, V phase and W phase, U phase differential current transformer, V phase differential current transformer and W phase differential current transformer are respectively provided in the neutral point side of U phase, V phase and W phase, and the coil for detecting generator current is integrated on the V phase differential current transformer.

[0006] Preferably, it further includes exciter and rotor winding, and the control output end of AVR voltage regulator is connected with exciter.

[0007] Preferably, the alternating current output end of exciter is converted into direct current through rotary rectifier and supplied to rotor winding.

[0008] Preferably, the permanent magnet machine power source is coaxial with rotor winding.

[0009] Preferably, the voltage transformer is further included, and the primary side terminals of the voltage transformer are connected with U-phase, V-phase and W-phase respectively, and the secondary side terminals of the voltage transformer are connected with the voltage detection end of the AVR voltage regulator.

[0010] Preferably, the pressure sensitive resistor is arranged in the electrical connection between the exciter and the rotor winding.

[0011] The technical effects and advantages of the utility model are as follows: the generator digital excitation system control circuit is coaxial with the generator rotor through the permanent magnet machine power source, and provides power source for the automatic voltage regulator when the generator operates; the permanent magnet machine power source has the advantages of voltage stability, no brush and no wireless interference; the permanent magnet machine power source is independent of the whole generator system and is not affected by the whole power supply system; the whole automatic voltage regulator power supply is more stable and efficient; a set of coils is integrated on the V-phase differential current transformer for detecting the current of the generator; the V-phase differential current transformer keeps the same shape, and the cost of the added coils is much lower than that of the original differential current transformer, thereby saving the limited space in the generator and reducing the labor cost. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 The utility model is a whole circuit schematic diagram.

[0013] In the drawing: 1, AVR voltage regulator; 2, permanent magnet machine power source; 3, U-phase differential current transformer; 4, V-phase differential current transformer; 5, W-phase differential current transformer; 6, coil; 7, rotor winding; 8, rotary rectifier; 9, voltage transformer; 10, exciter; 11, pressure sensitive resistor. DETAILED DESCRIPTION

[0014] The technical scheme in the utility model embodiment will be described clearly and completely in combination with the drawings in the utility model embodiment.

[0015] In order to save the space in the generator, refer to Figure 1As shown, including AVR voltage regulator 1, permanent magnet machine power source 2 and stator winding, the permanent magnet machine power source 2 is connected with AVR voltage regulator 1, for providing working power supply for it, the stator winding includes U phase, V phase and W phase, the U phase, V phase and W phase neutral point side is respectively provided with U phase differential current transformer 3, V phase differential current transformer 4 and W phase differential current transformer 5, the V phase differential current transformer 4 is integrated with the coil 6 for detecting generator current, through permanent magnet machine power source 2 and generator rotor coaxial, generator operation provides power source for automation voltage regulator, permanent magnet machine power source 2 as power source has the advantages of voltage stability, no brush, no wireless interference, at the same time, permanent magnet machine power source 2 is independent of the whole generator system, is not influenced by the whole power supply system, as a whole, AVR voltage regulator power supply is more stable and efficient, a set of coils 6 is integrated on V phase differential current transformer 4 for detecting the current of generator, the appearance of V phase differential current transformer 4 remains unchanged, and the cost of the added coil 6 is much lower than that of the original differential current transformer, thereby saving the limited space in the generator.

[0016] Further, including exciter 10 and rotor winding 7, the current input end of the exciter 10 is connected with the current output end of the automatic voltage regulator 1. The current transformer unit includes U phase differential current transformer 3, V phase differential current transformer 4 and W phase differential current transformer 5 arranged at the neutral point side of U phase, V phase and W phase. The V phase differential current transformer 4 is integrated with the coil 6 for detecting the current of the generator. The permanent magnet machine 2 is coaxial with the generator rotor. The AC output end of the exciter 10 is converted into DC through the rotary rectifier 8 to supply the rotor winding 7. The permanent magnet machine 2 is used as the power source of the automatic voltage regulator 1, which is independent, stable, efficient, and free of wireless interference, and is easy to maintain. The voltage transformer 9 is also included. The primary side terminals of the voltage transformer 9 are connected with U phase, V phase and W phase respectively. The secondary side terminals of the voltage transformer 9 are connected with the voltage detection end of the automatic voltage regulator 1. The voltage transformer 9 is used for the automatic voltage regulator 1 to detect voltage. Through the internal PID operation of the automatic voltage regulator 1, the stability of the generator output voltage is adjusted. By removing the V phase differential current transformer 4, a set of coils 6 or multiple sets of coils 6 are integrated in the differential current transformer to detect the current of the generator, which is used to calculate the load of the generator to realize the difference adjustment function to finally meet the demand of the generator parallel operation, and realize current detection and differential protection, save the limited space in the generator, and reduce the labor cost. The exciter 10 and the rotor winding 7 are electrically connected and provided with a pressure-sensitive resistor 11.

[0017] Finally, it should be noted that: the above only for preferred embodiments of the present application, and not for limiting the present application.

Claims

1. A generator digital excitation system control circuit, characterized in that: The invention comprises an AVR voltage regulator (1), a permanent magnet power source (2) and a stator winding, wherein the permanent magnet power source (2) is connected to the AVR voltage regulator (1) for providing a working power supply therefor, and the stator winding comprises a U phase, a V phase and a W phase, wherein the neutral point sides of the U phase, the V phase and the W phase are respectively provided with a U phase differential current transformer (3), a V phase differential current transformer (4) and a W phase differential current transformer (5), and the V phase differential current transformer (4) is integrated with a coil (6) for detecting the generator current.

2. The generator digital excitation system control circuit according to claim 1, characterized in that: It also includes an exciter (10) and a rotor winding (7), and the control output end of the AVR voltage regulator (1) is connected to the exciter (10).

3. The generator digital excitation system control circuit according to claim 2, characterized in that: The AC output end of the exciter (10) is converted into DC through a rotating rectifier (8) and supplied to the rotor winding (7).

4. The generator digital excitation system control circuit according to claim 3, characterized in that: The permanent magnet machine power source (2) is coaxial with the rotor winding (7).

5. The generator digital excitation system control circuit according to claim 1, characterized in that: It also includes a voltage transformer (9), wherein the primary side terminal of the voltage transformer (9) is respectively connected to the U phase, the V phase, and the W phase, and the secondary side terminal of the voltage transformer (9) is connected to the voltage detection terminal of the AVR voltage regulator (1).

6. The generator digital excitation system control circuit according to claim 4, characterized in that: A varistor (11) is provided in the electrical connection between the exciter (10) and the rotor winding (7).

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