Mixed type Continuous Var Compensation device in the low voltage complete set
Technical field:
The utility model relates to the mixed type Continuous Var Compensation device in a kind of low voltage complete set, and this device can carry out reactive power compensation to low voltage electric network, thereby effectively reduces the reactive power of electrical network, reduces line loss and improves power factor.
Background technology:
At present, the reactive power compensator in the low voltage complete set mainly is the parallel power condenser on electrical network, adjusts the reactive power of compensation by changing the capacitors count that drops into electrical network, thereby reaches the purpose that improves power factor.
The mode of switched capacitor generally has two kinds: a kind of is to utilize contactor to carry out switching, and another kind is to carry out switching by controllable silicon.Two kinds of switched capacitors all are that switching is carried out in classification, therefore the reactive power of compensation is phase step type, and electrical network can often be in to be owed to mend or cross the benefit state, and power factor all the time can not be close to 1, thereby the line loss of supply line can not effectively reduce, and the capacity of power supply unit can not be fully utilized.
Summary of the invention:
In order to overcome not high, the problem that can not Continuous Compensation of the power factor that existing common reactive power compensator exists, the utility model provides the device of the mixed type Continuous Var Compensation in a kind of low voltage complete set, this device can be realized the Continuous Compensation of power system reactive power, make power factor all the time close to 1, thereby effectively reduce the reactive power of electrical network, reduce line loss and improve the power supply unit utilance.
The technical scheme that its technical problem that solves the utility model adopts is: establish n by fixed capacity compensation circuit and 1 adjustable capacitor compensation loop by the silicon controlled module switching of contactor switching in mixed type Continuous Var Compensation device, each fixed capacity compensation circuit is identical with adjustable capacitor compensation tank capacitance capacity, and total compensation capacity is n+1.When mixed type Continuous Var Compensation device is worked, Intelligent Reactive Compensating Controller target power factor value can be made as 1, utilize this device that the low voltage bus side is detected, the reactive power and the power factor that detect are compared with set point, if the lagging reactive power of bus side is less than the capacity of single capacitor, then drop in Intelligent Reactive Compensating Controller control adjustable capacitor compensation loop, size by in good time change thyristor operating angle, adjust the reactive power of compensation, make power factor all the time close to 1; If the lagging reactive power of bus side is greater than single condenser capacity, then drop into 1 by the fixed capacity compensation circuit of contactor switching, then adjust the capacity in adjustable capacitor compensation loop, size by in good time change thyristor operating angle, adjust the output capacity in adjustable capacitor compensation loop, make power factor all the time close to 1, the rest may be inferred for all the other.Spend the added time when the reactive power of bus side, excise successively the fixed capacity compensation circuit, adopt the mode of switching cycle, by the output of Intelligent Reactive Compensating Controller control adjustable capacitor compensation tank capacitance amount, make power factor all the time close to 1 again.
The beneficial effects of the utility model are: this device can be realized the Continuous Compensation of power system reactive power, makes power factor all the time close to 1, thereby effectively reduces the reactive power of electrical network, reduces line loss and improves the power supply unit utilance.
Description of drawings:
The utility model is described in further detail below in conjunction with drawings and Examples.
Fig. 1 is the circuit theory diagrams that the utility model is implemented.
1. circuit breakers among the figure, 2. current transformer, 3. switch with knifeshaped fuse, 4. fuse, 5. contactor, 6. Intelligent Reactive Compensating Controller, 7. capacitor, 8. fuse, 9. thyristor throw-cut module, 10. capacitor.
Embodiment:
In the embodiment shown in fig. 1, the three-phase low-voltage inlet wire connects circuit breaker (1) upper end, mixed type Continuous Var Compensation device and load are attempted by circuit breaker (1) lower end, n fixed capacity compensation circuit and 1 adjustable capacitor compensation loop are attempted by the lower end of switch with knifeshaped fuse (3), the upper end of the lower termination contactor (5) of fuse (4), the lower termination capacitor (7) of contactor (5); The upper end of the lower termination thyristor throw-cut module (9) of fuse (8), the lower termination capacitor (10) of thyristor throw-cut module (9), the current input terminal of Intelligent Reactive Compensating Controller (6) is connected with current transformer (2), and its output is control contactor (5) and thyristor throw-cut module (9) respectively.During load running, Intelligent Reactive Compensating Controller (6) is compared power factor and the reactive power value of the bus side that detects through current transformer (2) with the set point of Intelligent Reactive Compensating Controller (6), such as the capacity of lagging reactive power less than 1 capacitor, Intelligent Reactive Compensating Controller (6) is output signal then, control adjustable capacitor compensation loop thyristor operating angle, regulate the capacitance of adjustable capacitor compensation loop output, make power factor close to 1; If Intelligent Reactive Compensating Controller (6) detects the capacity that lagging reactive power surpasses single electric capacity, then Intelligent Reactive Compensating Controller (6) output signal control contactor (5) adhesive, the fixed capacity compensation circuit drops into, simultaneously Intelligent Reactive Compensating Controller (6) output signal control adjustable capacitor compensation loop thyristor operating angle, regulate the capacitance of adjustable capacitor compensation loop output, make power factor close to 1, the rest may be inferred, and circulation drops into.It's the added time when reducing reactive power, pasts load, then excise successively each fixed capacity compensation circuit, then Intelligent Reactive Compensating Controller (6) output signal is controlled adjustable capacitor compensation loop thyristor operating angle, regulate the capacitance of adjustable capacitor compensation loop output, thereby make power factor all the time close to 1.