A kind of circuit longitudinal differential protection method of substation areas of transformer station information takenTechnical field
The present invention relates to Relay Protection Technology in Power System field, be specifically related to a kind of circuit longitudinal differential protection method of substation areas of transformer station information taken.
Background technology
Along with a large amount of accesses with distributed energy that increase rapidly of power load, power grid construction obtains and develops fast, but it is in short supply by land resource, earth clearance is difficult, there is the various factors such as mistake in understanding in citizen to power transmission and transforming equipment electromagnetic radiation, the floor space of current transformer substation is more and more less, especially for the traction substation of high-speed railways, the floor space of the transformer station that the one-end substation of industrial and mining enterprises etc. are special is also limited further, therefore, often inlet wire CT cannot be installed in point of incoming cables, inlet wire cannot configure longitudinal differential protection, when distribution line is shorter, also syllogic distance protection cannot be configured, thus cause inlet wire cannot configure to have and optionally protect fast, reduce reliability and the fail safe of transformer station.
Summary of the invention
Technical problem solved by the invention is that the floor space of existing transformer station is limited, and inlet wire CT often cannot be installed in point of incoming cables, causes inlet wire cannot configure to have and optionally protect fast, reduces the reliability of transformer station and the problem of fail safe.The circuit longitudinal differential protection method of substation areas of transformer station information taken of the present invention; can when substation line do not install carry out CT; realize the longitudinal differential protection with selectivity and gamut quick-action, improve reliability and the fail safe of transformer station, have a good application prospect.
In order to achieve the above object, the technical solution adopted in the present invention is:
A circuit longitudinal differential protection method for substation areas of transformer station information taken, is characterized in that: comprise the following steps,
Step (1), this station, side domain information aggregating apparatus gathers spaced electric current on the bus of transformer lines place; If transformer bay every bus bar side without CT, then other sides of transformer are inputted as interval;
Step (2), this station, side domain information aggregating apparatus obtains electric pressure, CT no-load voltage ratio, the corner mode at each interval, and by the electric current reduction at each interval in the corresponding interval at circuit place;
Step (3), the electric current at each interval after reduction by summation, is formed the incomplete differential current I of this side by this station, side domain information aggregating apparatusdM, as shown in formula (1),
IdM＝IM2+IM3+…+IMn(1)
Wherein, Im2~ Imnfor each spacing current after reduction;
Step (4), this station, side domain information aggregating apparatus, by stalling current account form, as shown in formula (2), forms the half braking electric current I of this siderM,
IrM＝|IM2|+|IM3|+…+|IMn|(2)
Wherein, Im2~ Imnfor each spacing current after reduction;
Step (5), this station, side domain information aggregating apparatus is connected with offside line protective devices by circuit optical fiber passage, completes data syn-chronization and the transmission of this side and offside, receives the electric current I of offsiden, according to formula (3), formula (4), obtain the longitudinal differential protection difference stream I of this sidedwith longitudinal differential protection stalling current Ir,
Id＝IdM+IN(3)
Ir＝IrM+|IN|(4)
And send the longitudinal differential protection difference stream I of this sidedwith longitudinal differential protection stalling current Ir, realize circuit longitudinal differential protection.
The circuit longitudinal differential protection method of aforesaid substation areas of transformer station information taken; it is characterized in that: step (1); gather spaced electric current on the bus of place, this side line road; acquisition mode comprises routine sampling access and digital sampling access; described routine sampling access is for instrument transformer is by cable access station domain information aggregating apparatus, and described digital sampling access comprises point-to-point sample mode and networking sample mode.
The invention has the beneficial effects as follows: the circuit longitudinal differential protection method of substation areas of transformer station information taken of the present invention; can when substation line do not install carry out CT; realize the longitudinal differential protection with selectivity and gamut quick-action; improve reliability and the fail safe of transformer station, have a good application prospect.
Accompanying drawing explanation
Fig. 1 is the flow chart of the circuit longitudinal differential protection method of substation areas of transformer station information taken of the present invention.
Fig. 2 is the schematic diagram of this station, side domain information aggregating apparatus current acquisition of the present invention and transmission.
Embodiment
Below in conjunction with Figure of description, the present invention is further illustrated.
The circuit longitudinal differential protection device of substation areas of transformer station information taken of the present invention, can when substation line do not install carry out CT, realize having the longitudinal differential protection of selectivity and gamut quick-action; improve reliability and the fail safe of transformer station; as shown in Figure 1, comprise the following steps
This station, side domain information aggregating apparatus of step (1) gathers spaced electric current on the bus of circuit place; , as shown in Figure 2, this side is M side, and offside is N side, if transformer bay every bus bar side without CT, then other sides of transformer are inputted as interval;
Gather spaced electric current on the bus of transformer lines place, acquisition mode comprises routine sampling access and digital sampling access, described routine sampling access is for instrument transformer is by cable access device, and described digital sampling access comprises point-to-point sample mode and networking sample mode;
Step (2), this station, side domain information aggregating apparatus obtains electric pressure, CT no-load voltage ratio, the corner mode at each interval, and by the electric current reduction at each interval in the corresponding interval at circuit place;
Step (3), the electric current at each interval after reduction by summation, is formed the incomplete differential current I of this side by this station, side domain information aggregating apparatusdM, as shown in formula (1),
IdM＝IM2+IM3+…+IMn(1)
Wherein, Im2~ Imnfor each spacing current after reduction;
Step (4), this station, side domain information aggregating apparatus, by stalling current account form, as shown in formula (2), forms the half braking electric current I of this siderM,
IrM＝|IM2|+|IM3|+…+|IMn|(2)
Wherein, Im2~ Imnfor each spacing current after reduction;
Step (5), this station, side domain information aggregating apparatus is connected with offside line protective devices by circuit optical fiber passage, completes data syn-chronization and the transmission of this side and offside, receives the electric current I of offsiden, according to formula (3), formula (4), obtain the longitudinal differential protection difference stream I of this sidedwith longitudinal differential protection stalling current Ir,
Id＝IdM+IN(3)
Ir＝IrM+|IN|(4)
And send the longitudinal differential protection difference stream I of this sidedwith longitudinal differential protection stalling current Ir, realize circuit longitudinal differential protection.
In sum; the circuit longitudinal differential protection method of substation areas of transformer station information taken of the present invention; can when substation line do not install carry out CT; realize the longitudinal differential protection with selectivity and gamut quick-action; improve reliability and the fail safe of transformer station, have a good application prospect.
More than show and describe general principle of the present invention and principal character and advantage of the present invention.The technical staff of the industry should understand; the present invention is not restricted to the described embodiments; what describe in above-described embodiment and specification just illustrates principle of the present invention; without departing from the spirit and scope of the present invention; the present invention also has various changes and modifications, and these changes and improvements all fall in the claimed scope of the invention.Application claims protection range is defined by appending claims and equivalent thereof.