CN106655932A - Dual low excitation restriction method for generator depth phase leading of overseas small power grid project - Google Patents

Abstract

The invention belongs to the technical field of power and particularly relates to a dual low excitation restriction method for generator depth phase leading of an overseas power grid project with relatively small capacity. In the overseas small power grid system project, a set of low excitation restriction is set in a DCS (Distributed Control System); low excitation restriction curves of generator power angles of 70 degrees corresponding to different active power are calculated through a formula; the low excitation restriction curves are logically set in the DCS; a matching relationship between DCS low excitation restriction, namely, PQ restriction and generator excitation loss curves is checked, the DCS low excitation restriction acts first, then the PQ restriction acts, and excitation loss protection acts; when generator phase leading is operated and the depth reaches an action value of the DCS low excitation restriction, the DCS gives an alarm and restricts "excitation reduction" operation, and the DCS low excitation restriction is disabled; and when a unit is normal, the DCS low excitation restriction is enabled, and when scheduling requires the depth of the unit and the depth reaches the action value of the DCS low excitation restriction, the DCS low excitation restriction exits. The low excitation restriction of reactive power is provided according to different active power, so that the misoperation is effectively avoided.

Description

Overseas minor scale power net project generator depth enters that phase is double low to encourage method for limiting

Art

The invention belongs to technical field of electric power, more particularly to a kind of less project generator depth of overseas net capacity enters phase It is double low to encourage method for limiting.I.e. existing excitation system is low encourage restriction under conditions of, increase in a set of DCS system low encourages limit System, when DCS is low encourage restriction and reach working value when, limiting operations staff carries out " excitation reduction " operation, and sends corresponding alarm signal Number.

Background technology

When in overseas minor scale power net project generator depth enters phase, low in excitation system is encouraged restriction and is typically based on power supply agreement Requirement adjusted, enter that phase depth is deeper due to what is required in electric power system, generator can not be met for stability margin Require, i.e. generator's power and angle δ is less than 70 °.In some cases, power the requirement of agreement to reach unit, generator operation Generator rotor angle may already exceed 85 °, and this is very unfavorable for generator stable operation.

The content of the invention

For above-mentioned problems of the prior art, the invention provides a kind of overseas minor scale power net project generator depth Enter phase it is double it is low encourage method for limiting, main purpose is to limit unit to enter the not enough region of stability margin.In order to meet power supply agreement Requirement, what is arranged in excitation system low encourage restriction and can not limit and remind operations staff by generator operation to stability margin Not enough region.

In order to realize foregoing invention purpose, the present invention is achieved in the following ways：

Overseas minor scale power net project generator depth enter phase it is double it is low encourage method for limiting, in being minor scale power net system engineering in overseas, In DCS system it is fixed it is a set of it is low encourage restriction, specifically include following steps：

A, different active corresponding generator's power and angles are calculated by formula is that 70 ° low encourages restrictive curve；

B, low restrictive curve logic of encouraging is made in DCS system；

C, verification DCS is low encourages restrictions, and excitation system is low to encourage restriction i.e. PQ restrictions, and loss of exicitation curve fitting relation, DCS is low to encourage restriction action first, and PQ limits subsequent action, the final action of field loss protection；

D, enter phase when operations staff's operation generator, when depth reaches that DCS is low to encourage restriction working value, DCS reports to the police, and limits Operations staff's further " excitation reduction " operation, according to actual conditions, selects the low throwings for encouraging restriction of DCS to move back；

E, when unit normal condition, select that DCS is low encourages restriction " input ", when scheduling requirement unit depth, and reach DCS is low when encouraging restriction working value, selects low " the exiting " for encouraging restriction of DCS.

Described to calculate different active corresponding generator's power and angles by formula be that 70 ° low encourages restrictive curve, is referred to logical Cross following formula (1) calculate corresponding to generator's power and angle δ less than 70 ° generated power and idle curve：

In formula (1)：P is generator active power, and U generator terminal voltages, Xq is generator synchronous reactance, and Q is to send out Motor reactive power, δ is generator's power and angle.

Advantages of the present invention and beneficial effect are：

(1) the low of reactive power can be provided according to different active power and encourages restriction.

(2) maloperation of operations staff can be effectively avoided, when phase depth is entered more than 70 ° of generator rotor angle, DCS can be limited simultaneously Report to the police.And can choose whether to carry out continuation operation according to actual conditions.

(3) to entering phase based on overseas minor scale power net project generator depth, low in excitation system encourage limit with it is low in DCS Encouraging restriction can effectively coordinate.

Below in conjunction with the accompanying drawings and specific embodiment, the present invention is further detailed explanation.

Description of the drawings

Fig. 1 is control flow chart of the present invention；

Fig. 2 is that generator is low in DCS encourages restrictive curve；

Fig. 3 is limited and field loss protection fitting curves for actual low encouraging.

Specific embodiment

The present invention is that a kind of overseas minor scale power net project generator depth phase modifier group pair is low encourages method for limiting, as shown in figure 1, Fig. 1 is control flow chart of the present invention, and Fig. 2 is that generator is low in DCS encourages restrictive curve, and Fig. 3 is that actual low encouraging limits and loss of excitation guarantor Shield fitting curves.

In overseas in minor scale power net system engineering, in some cases, the unit of protocol requirement of powering enters phase depth and has surpassed Generator operation generator rotor angle is crossed and has been limited to 70 °, in order to limit the maloperation of operations staff, equally set a set of in DCS system Low to encourage restriction, low the encouraging of this set limits the requirement for meeting generator operation generator rotor angle, i.e. generator rotor angle less than 70 °.Simultaneously operations staff can root Encourage restriction and carry out " throwing is moved back " according to actual conditions are low to DCS.

A kind of overseas minor scale power net project generator depth of the present invention enter phase it is double it is low encourage method for limiting, specifically include following step Suddenly：

1st, it is that 70 ° low encourages restrictive curve to calculate different active corresponding generator's power and angles by formula (1).

2nd, low restrictive curve logic of encouraging is made in DCS system.DCS represents dcs.

3rd, DCS is low encourages restriction for verification, and excitation system is low to encourage restriction (PQ restrictions), with loss of exicitation curve fitting relation such as Shown in Fig. 3.

4th, when operations staff's operation generator enters phase, when depth reaches that DCS is low to encourage restriction working value, DCS reports to the police, and limits Operations staff's further " excitation reduction " operation.Operations staff can select low " throwing is moved back " for encouraging restriction of DCS according to actual conditions.

5th, when unit normal condition, select that DCS is low encourages restriction " input ", when scheduling requirement unit depth, and reach DCS is low when encouraging restriction working value, selects low " the exiting " for encouraging restriction of DCS.

The present invention in the specific implementation, is further added by dcs that set of excitation system is low to encourage restriction, active in generator difference In the case of power, by calculating to formula (1) corresponding to generator's power and angle δ less than 70 ° of generated power and idle Curve, as shown in Figure 2.

In formula (1)：P is generator active power, and U generator terminal voltages, Xq is generator synchronous reactance, and Q is to send out Motor reactive power, δ is generator's power and angle.

When under a certain active power, generator enters during phase, encourage restriction and have work value when reactive power is low less than DCS, Forbidding operations staff to continue carries out " excitation reduction " operation.Can cancel that DCS is low to be encouraged restriction and carry out by DCS buttons after confirmation Subsequent operations.

Overseas certain project pair is low to encourage restriction example, as shown in Table 1 and Table 2.

1. it is that 70 ° low encourages restrictive curve to calculate different active corresponding generator's power and angles by formula (1).Such as Fig. 3 Middle DCS is low to encourage restrictive curve.

2nd, low restrictive curve logic of encouraging is made in DCS system.DCS represents dcs.

3rd, DCS is low encourages restriction for verification, and excitation system is low to encourage restriction (PQ restrictions), with loss of exicitation curve fitting relation. As shown in Figure 3 DCS is low encourages restrictive curve, PQ restrictive curves, and loss of excitation characteristic curve has that preferable matching relationship, i.e. DCS are low to encourage limit System action first, PQ limits subsequent action, the final action of field loss protection.

4th, when operations staff's operation generator enters phase, when depth reaches that DCS is low to encourage restriction working value, DCS reports to the police, and limits Operations staff's further " excitation reduction " operation.Operations staff can select low " throwing is moved back " for encouraging restriction of DCS according to actual conditions.

5th, when unit normal condition, select that DCS is low encourages restriction " input ", when scheduling requirement unit depth, and reach DCS is low when encouraging restriction working value, selects low " the exiting " for encouraging restriction of DCS.

Table .1 leading phase tests calculate desired parameters list

Table .2 generator leading phase test data

Claims (2)

1. overseas minor scale power net project generator depth enter phase it is double it is low encourage method for limiting, it is characterized in that：Minor scale power net system work in overseas Cheng Zhong, in DCS system it is fixed it is a set of it is low encourage restriction, specifically include following steps：

A, different active corresponding generator's power and angles are calculated by formula is that 70 ° low encourages restrictive curve；

B, low restrictive curve logic of encouraging is made in DCS system；

C, verification DCS are low to encourage restriction, and the low i.e. PQ of restriction that encourages of excitation system is limited, and with loss of exicitation curve fitting relation, DCS is low Restriction action first is encouraged, PQ limits subsequent action, the final action of field loss protection；

D, enter phase when operations staff's operation generator, when depth reaches that DCS is low to encourage restriction working value, DCS reports to the police, and limits operation Personnel's further " excitation reduction " operation, according to actual conditions, selects the low throwings for encouraging restriction of DCS to move back；

E, when unit normal condition, select that DCS is low encourages restriction " input ", when scheduling requirement unit depth, and it is low to reach DCS When encouraging restriction working value, low " the exiting " for encouraging restriction of DCS is selected.

2. overseas minor scale power net project generator depth according to claim 1 enter phase it is double it is low encourage method for limiting, it is characterized in that： Described to calculate different active corresponding generator's power and angles by formula be that 70 ° low encourages restrictive curve, is referred to by following public affairs Formula (1) calculates the generated power and idle curve corresponding to generator's power and angle δ less than 70 °：

$tan\mathrm{\δ}=\frac{{\mathrm{PX}}_q}{U^2+{\mathrm{QX}}_q}---\left(1\right)$

In formula (1)：P is generator active power, and U generator terminal voltages, Xq is generator synchronous reactance, and Q is generator Reactive power, δ is generator's power and angle.