Adjustment mechanism and adjustment method of dynamic time constant of generator for simulation

Abstract

The invention discloses an adjustment mechanism for the dynamic time constant of a simulation generator and an adjustment method thereof, which solves the problem of how to make the per-unit value of the dynamic time constant of a simulation motor consistent with the per-unit value of a design prototype in an existing simulation experiment. A dumbbell-shaped annular iron core skeleton (4) is sleeved on the shaft end of the non-driving end of a simulation generator shaft (1) between the simulation generator rotor iron core (3) and a rotating rectifier (8), a reactor coil (6) is arranged in the middle groove of the dumbbell-shaped annular iron core skeleton (4) on a damping copper sleeve (7), a yoke ring sheath (5) is arranged on the reactor coil (6), and the reactor coil (6) is connected in series with a rotor excitation winding (2) and then connected between the positive and negative poles of the rotating rectifier (8); the per-unit value of the dynamic time constant of the simulation motor is consistent with the per-unit value of the design prototype as much as possible.

Description

Technical Field

[0001] The invention relates to a generator, and in particular to an adjustment mechanism and an adjustment method for a dynamic time constant of a simulated generator used when verifying the running stability and dynamic performance of a designed large-scale generator. Background Art

[0002] When designing the electromagnetic system of a new large synchronous generator, in order to predict the stability and dynamic performance of the designed large generator during future operation and reduce the risk of electromagnetic design errors of the large generator, a simulation verification method of simulating large generators is usually used to simulate and verify the electromagnetic parameters of the designed large generator. The specific method is: build a simulation platform for the designed large motor in the laboratory, use a simulation test generator with a capacity much smaller than that of the large synchronous generator to simulate the large-capacity synchronous generator; use some simulated load equipment and power grid equipment to simulate the power grid and load; use a dedicated control system and control software to control the relevant simulation experimental equipment and systems, so that the actual The physical simulation hardware and simulation software together constitute an experimental simulation generator system to simulate various steady-state and dynamic operating conditions, as well as fault conditions of the designed large-scale synchronous generator, so as to verify the reliability and stability of the electromagnetic performance of the designed large-scale synchronous generator and guide the design process of designers; the above-mentioned simulation experimental generator set is an important equipment of the simulation system. The electromagnetic performance parameters of the simulation experimental generator set need to be basically close to the electromagnetic performance parameters of the simulated generator set, especially some impedance parameters and time constants, among which the main time constants include the excitation winding time constant when the armature winding is open-circuited, the direct-axis transient time constant, the direct-axis super-transient time constant, and the armature time constant.

[0003] In the simulation platform of large motors, the simulated generator set is an important device of the simulation system. The prime mover and generator of the simulated generator set must be equal to the parameter per unit value of the prototype, and various inertia times must be consistent with the prototype. Since the designed prototype and the dynamically simulated generator have huge differences in basic parameters such as capacity, voltage, volume, weight, inertia, etc., it is impossible to completely achieve the same per unit value of various performance parameters, especially some dynamic parameters and inertia time constants, which cannot be satisfied at the same time. This requires some auxiliary devices to flexibly adjust certain dynamic parameters; for example, the excitation winding time constant T of the designed motor d0 , transient current time constant T d '、Super transient time constant T d In order to simulate the per-unit value of the "simulated generator", it is necessary to add some devices to the simulation platform and the simulated motor to make the per-unit value of the simulated generator as consistent as possible with the designed prototype. Summary of the invention

[0004] The present invention provides an adjustment mechanism and an adjustment method for the dynamic time constant of a generator for simulation, which solves the technical problem of how to make the per-unit value of the dynamic time constant of a simulated motor as consistent as possible with the per-unit value of a designed prototype in existing simulation experiments.

[0005] The present invention solves the above technical problems through the following technical solutions:

[0006] The general concept of the present invention is: due to the large generator designed, including the excitation winding time constant T d0 The dynamic time constants of the generator excitation winding are large. In the simulation, in order to get as close to these parameters as possible, we can only make some efforts to determine the relevant values ​​of these parameters. In the simulation, the excitation winding time constant T of the generator is simulated. d0 It is proportional to the per-unit value of the excitation rotor winding reactance of the simulated generator and inversely proportional to the per-unit value of the excitation rotor winding resistance of the simulated generator. Therefore, the excitation winding time constant T of the simulated generator can be increased by reducing the per-unit value of the excitation rotor winding resistance of the simulated generator. d0 This method is feasible in simulation experiments, but to a limited extent, because the per-unit value of the excitation rotor winding resistance can be reduced by increasing the cross-sectional area of ​​the copper wire in the excitation rotor winding of the simulated generator, but the increase in the cross-sectional area of ​​the copper wire in the excitation rotor winding is limited, otherwise, the excitation winding will be very large and cannot be made and used on site. Another method is to increase the per-unit value of the reactance of the excitation rotor winding of the simulated generator, which encounters the problem of how to connect a large inductor in series with the rotor of the rotating simulated generator. At the same time, it is also necessary to solve how to make the inductor in series only act as an impedance for static inductance or low frequency, and reduce the influence on high frequency or transient reactance. The present invention creatively arranges an iron core frame on the rotor of the simulated generator, and arranges a reactor coil that can rotate with the rotor on the iron core frame. By adjusting the reactance value of the reactor coil, the time constant T of the excitation winding of the simulated generator is increased. d0 For the purpose of this, a good conductor copper sleeve is set under the inner layer of the series-connected reactor coil. When the coil current changes suddenly or is a high-frequency current, a reverse or opposite-phase circulating current is induced in the copper sleeve to weaken the impedance of the coil current mutation and high frequency. That is, the reactor has a strong damping effect on low-frequency and slowly changing currents, and exhibits low impedance characteristics for sudden currents and high-frequency changing currents, which can effectively increase the relevant time constant of the synchronous motor and delay the transition process, so that a dynamic analog generator with a very small capacity has an electrical time constant similar to or even the same as that of a large motor.

[0007] A mechanism for adjusting the dynamic time constant of a simulation generator comprises a simulation generator shaft, a simulation generator rotor core is arranged on the simulation generator shaft, a rotor excitation winding is arranged in the simulation generator rotor core, a rotating rectifier and an exciter rotor are arranged on the shaft end of the non-driving end of the simulation generator shaft, an exciter rotor three-phase winding is arranged in the exciter rotor, a dumbbell-shaped annular iron core skeleton is sleeved on the shaft end of the non-driving end of the simulation generator shaft between the simulation generator rotor core and the rotating rectifier, a damping copper sleeve is arranged at the annular groove bottom of the middle groove of the dumbbell-shaped annular iron core skeleton, a reactor coil is arranged in the middle groove of the dumbbell-shaped annular iron core skeleton on the damping copper sleeve, a yoke ring sleeve is arranged on the reactor coil, and the yoke ring sleeve and the dumbbell-shaped annular iron core skeleton form an annular closed magnetic circuit; the reactor coil is connected in series with the rotor excitation winding and then connected between the positive and negative poles of the rotating rectifier.

[0008] The three-phase voltage input terminal of the rotating rectifier is connected with the three-phase winding of the exciter rotor.

[0009] A method for adjusting the dynamic time constant of a generator for simulation is characterized by the following steps: adjusting the cross section of the copper wire in the reactor coil to adjust the per-unit value of the excitation rotor winding resistance of the simulated generator; adjusting the number of turns of the reactor coil or the core size of the dumbbell-shaped annular core skeleton to adjust the per-unit value of the excitation rotor winding reactance of the simulated generator; thereby making the dynamic time constant of the dynamic simulation generator with a smaller capacity close to the dynamic time constant of the designed large motor.

[0010] The present invention provides a simulation experiment method for making the per-unit value of the dynamic time constant of the simulated motor as consistent as possible with the per-unit value of the designed prototype in the simulation experiment, so that the simulation machine can achieve the time constant as close as possible to the designed large-scale generator; in particular, the reactor coil structure in the dumbbell-shaped annular iron core skeleton of the present invention creatively provides a dynamically adjustable test means for the simulation experiment, especially the damping copper sleeve provided at the bottom of the annular groove of the middle groove plays a positive role in smoothing the fluctuation of the excitation current. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic diagram of the mechanical connection structure of the present invention;

[0012] Figure 2 It is a schematic diagram of the electrical connection structure of the present invention. DETAILED DESCRIPTION

[0013] The present invention is described in detail below in conjunction with the accompanying drawings:

[0014] A mechanism for adjusting the dynamic time constant of a simulation generator, comprising a simulation generator shaft 1, a simulation generator rotor core 3 is arranged on the simulation generator shaft 1, a rotor excitation winding 2 is arranged in the simulation generator rotor core 3, a rotating rectifier 8 and an exciter rotor are arranged on the non-driving end of the simulation generator shaft 1, an exciter rotor three-phase winding 9 is arranged in the exciter rotor, and a rotation winding 2 is arranged between the simulation generator rotor core 3 and the rotating rectifier 8. A dumbbell-shaped annular iron core skeleton 4 is sleeved on the shaft end of the non-driving end of the simulation generator shaft 1, a damping copper sleeve 7 is arranged at the annular groove bottom of the middle groove of the dumbbell-shaped annular iron core skeleton 4, a reactor coil 6 is arranged in the middle groove of the dumbbell-shaped annular iron core skeleton 4 on the damping copper sleeve 7, a yoke ring sleeve 5 is arranged on the reactor coil 6, and the yoke ring sleeve 5 and the dumbbell-shaped annular iron core skeleton 4 form an annular closed magnetic circuit; the reactor coil 6 is connected in series with the rotor excitation winding 2 and then connected between the positive and negative poles of the rotating rectifier 8.

[0015] The three-phase voltage input terminal of the rotating rectifier 8 is connected to the three-phase winding 9 of the exciter rotor.

[0016] A method for adjusting the dynamic time constant of a generator for simulation is characterized by the following steps: adjusting the cross section of the copper wire in the reactor coil 6 to adjust the per-unit value of the excitation rotor winding resistance of the simulated generator; adjusting the number of turns of the reactor coil 6 or the core size of the dumbbell-shaped annular iron core skeleton 4 to adjust the per-unit value of the excitation rotor winding reactance of the simulated generator; thereby making the dynamic time constant of the dynamic simulation generator with a smaller capacity close to the dynamic time constant of the designed large motor; the dumbbell-shaped annular iron core skeleton 4 and the yoke ring sheath 5 together constitute the magnetic circuit part of the reactor, when the reactor coil 6 is passed through a direct current I, a magnetic flux Φ is generated in the iron core magnetic circuit, and its inductance L=WΦ / I, wherein W is the number of coil turns, and when the number of coil turns W is adjusted or the core size is changed, the inductance L can be changed, thereby achieving the purpose of adjusting the inductance of the excitation winding, and further achieving the adjustment of the time constants such as Td0, Td', and Td" of the synchronous generator.

Claims

1. A method for adjusting the dynamic time constant of a simulation generator, which is performed by an adjustment mechanism for the dynamic time constant of the simulation generator, wherein the adjustment mechanism for the dynamic time constant of the simulation generator comprises a simulation generator shaft (1), a simulation generator rotor core (3) is arranged on the simulation generator shaft (1), a rotor excitation winding (2) is arranged in the simulation generator rotor core (3), a rotating rectifier (8) and an exciter rotor are arranged on the non-driving end of the simulation generator shaft (1), an exciter rotor three-phase winding (9) is arranged in the exciter rotor, and a rotor between the simulation generator rotor core (3) and the rotating rectifier (8) is arranged. A dumbbell-shaped annular iron core frame (4) is sleeved on the shaft end of the non-driving end of the simulation generator shaft (1); a damping copper sleeve (7) is arranged at the annular groove bottom of the middle groove of the dumbbell-shaped annular iron core frame (4); a reactor coil (6) is arranged in the middle groove of the dumbbell-shaped annular iron core frame (4) on the damping copper sleeve (7); a yoke ring sleeve (5) is arranged on the reactor coil (6); the yoke ring sleeve (5) and the dumbbell-shaped annular iron core frame (4) form an annular closed magnetic circuit; the reactor coil (6) is connected in series with the rotor excitation winding (2) and then connected between the positive and negative poles of a rotating rectifier (8); the three-phase voltage input end of the rotating rectifier (8) is connected with the exciter rotor three-phase winding (9); the characteristics are as follows: Follow these steps: By adjusting the cross section of the copper wire in the reactor coil (6), the per unit value of the excitation rotor winding resistance of the simulated generator can be adjusted; by adjusting the number of turns of the reactor coil (6) or the core size of the dumbbell-shaped annular iron core frame (4), the per unit value of the excitation rotor winding reactance of the simulated generator can be adjusted; thereby, the dynamic time constant of the dynamic simulated generator with a smaller capacity is made close to the dynamic time constant of the designed large generator.

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