The utility model content
In order to solve the insulating requirements height of the high-voltage mutual inductor that exists in the prior art, in the 10Kv electric system is must have a power failure and could overhaul after 42Kv, secondary rated load have 10VA so volume and weight are all quite big, price is high, installing space is big and adopt Wuhan state survey company to design the high-voltage electric energy meter electron device all because of it all to be operated in high-pressure side,, fault high to reliability requirement, and it is big on high-tension side power taking difficulty, reliability is difficult to guarantee these technical matterss, and the utility model provides a kind of three-phase four-wire high voltage energy table.
The technical scheme that the prior art problem that solves the utility model is adopted is: a kind of three-phase four-wire high voltage energy table is provided, described three-phase four-wire high voltage energy table comprises: the voltage transformer (VT) unit, current transformer unit and three-phase four-wire low-voltage electric energy meter, wherein, described voltage transformer (VT) unit one termination is gone into high voltage bus, the other end inserts the earth by ground terminal, described current transformer units in series is on high voltage bus, and the input end of described three-phase four-wire low-voltage electric energy meter is connected with the output terminal of described voltage transformer (VT) unit with described current transformer unit.
According to an optimal technical scheme of the present utility model: described voltage transformer (VT) unit is resistance-type partial pressure unit or capacitive partial pressure unit.
According to an optimal technical scheme of the present utility model: described current transformer unit be the low-power current transformer and with described low-power current transformer parallel resistor.
According to an optimal technical scheme of the present utility model: the coaxial cable connector that is connected to the band shielding of described voltage transformer (VT) unit and described current transformer unit or the coaxial cable connector of band double shield.
According to an optimal technical scheme of the present utility model: described voltage transformer (VT) unit and described current transformer unit operate in the hi-line terminal.
According to an optimal technical scheme of the present utility model: but described current transformer unit is sieve Paderewski coil.
According to an optimal technical scheme of the present utility model: described three-phase four-wire high voltage energy table comprises power module, peripheral module, central processor unit and electric energy computation chip, wherein, described electric energy computation chip, described power module and described peripheral module are connected with described central processor unit respectively.
After comparing with existing technical scheme, useful effect of the present utility model is: with respect to High-voltage measuring box (cabinet), the high-voltage electric-energy meter volume in the technical solutions of the utility model is small and exquisite, in light weight; Survey the high-voltage electric energy meter of company with respect to Wuhan state, the high-voltage electric energy meter in the technical solutions of the utility model is operated in low-pressure side, and simplicity of design, reliability height are with low cost.
Embodiment:
The utility model is described in further detail below in conjunction with drawings and Examples:
Among the figure: A, B, the primary current conductor 1 of C three-phase electrical power system, voltage transformer (VT) unit 2, current transformer unit 3, central processor unit 4, electric energy computation chip 5, three-phase four-wire low-voltage electric energy meter 6, peripheral module 7, power module 8, connecting line 9, ground terminal 10, current integrator 11, multiplier 12, SPI interface 13, resistance 14, low-power current transformer 15, but sieve Paderewski coil 16, the high-pressure side divider resistance 17 of Resistive Voltage Transformer, the low-pressure side divider resistance 18 of Resistive Voltage Transformer, the high-pressure side dividing potential drop electric capacity 19 of capacitance type potential transformer, the low-pressure side dividing potential drop electric capacity 20 of capacitance type potential transformer.
See also three-phase four-wire high voltage energy measuring method process flow diagram in a kind of three-phase four-wire high voltage energy measuring method of Fig. 1 the utility model and the device.As shown in Figure 1, described three-phase four-wire high voltage energy measuring method comprises step: the first, the high-voltage large current conversion of signals is become the little current signal of low-voltage; The second, the little current signal of described low-voltage is inserted the three-phase four-wire system electric power meter and carry out electric energy measurement.
Method in the first step described in the optimal technical scheme of the present utility model is: by voltage transformer (VT) unit 2 high voltage signal is converted to
Low voltage signal, big current signal is transformed to the little current signal of low-voltage of 225mV by current transformer unit 3.Described second step comprises substep: one, the little current signal of low-voltage with described 225mV carries out Signal Regulation; Two, the signal after will regulating inserts current/voltage multiplier 12 input ends of metering input mutually of one among A, B, the C of three-phase electric energy chip in the three-phase four-wire system electric power meter; Three, other two-phases also are input to the input end of the current/voltage multiplier 12 of metering input; Four, obtain electrical energy pulse output by described current/voltage multiplier 12 and time integral; Five, by SPI interface 13 data are sent to central processor unit 4 and carry out electric energy measurement.
See also three-phase four-wire high voltage energy table modular structure synoptic diagram in a kind of three-phase four-wire high voltage energy measuring method of Fig. 2 the utility model and the device.As shown in FIG.: described three-phase four-wire high voltage energy table comprises: voltage transformer (VT) unit 2, current transformer unit 3 and three-phase four-wire low-voltage electric energy meter 6, wherein, described voltage transformer (VT) unit 2 one terminations are gone into high voltage bus, the other end inserts the earth by ground terminal 10, described current transformer unit 3 is connected on the high voltage bus, and the input end of described three-phase four-wire low-voltage electric energy meter 6 is connected with the output terminal of described voltage transformer (VT) unit 2 with described current transformer unit 3.
2 are the coaxial cable connector of band shielding or the coaxial cable connector of band double shield with the connecting line 9 of described current transformer unit 3 in voltage transformer (VT) unit described in the optimal technical scheme of the present utility model.Described three-phase four-wire low-voltage electric energy meter 6 comprises power module 8, peripheral module 7, central processor unit 4 and electric energy computation chip 5, wherein, described electric energy computation chip 5, described power module 8 and described peripheral module 7 are connected with described central processor unit 4 respectively.
See also the three-phase four-wire high voltage energy table modular structure synoptic diagram after Fig. 3 adopts low-power current transformer 15, among the figure, described current transformer unit 3 adopts low-power current transformer 15, as shown in Figure 3, then export Vi=Ki * I * R by being connected in series a small resistor behind the current signal that electromagnetic induction produces with primary current is directly proportional; I is a primary side current in the formula, and K is the LPCT no-load voltage ratio, and R is the high precision small resistor, and Vi is a current transformer parallel resistance output signal.
See also the three-phase four-wire high voltage energy table modular structure synoptic diagram after but Fig. 4 adopts sieve Paderewski coil 16, among the figure, but described current transformer unit 3 adopts sieve Paderewski air core coil, as shown in Figure 4, produce voltage signal e (t)=Di * dI/dt that is directly proportional with the primary current differential by electromagnetic induction; I is a primary side current in the formula, the Di differential coefficient, e (t) but be sieve Paderewski air core coil output signal.
Three-phase four-wire high voltage energy table modular structure synoptic diagram behind the described voltage transformer (VT) unit 2 employing resistance dividers produces one and primary voltage V corresponding voltage signal Vv=Kv * V by dividing potential drop as shown in Figure 5; V is the primary side voltage signal in the formula, and Kv is a voltage change ratio, and Vv is the voltage after partial signal.
Three-phase four-wire high voltage energy table modular structure synoptic diagram behind the described voltage transformer (VT) unit 2 employing condenser dividers produces one and primary voltage V corresponding voltage signal Vv=Kv * V by dividing potential drop as shown in Figure 6; V is the primary side voltage signal in the formula, and Kv is a voltage change ratio, and Vv is the voltage after partial signal.
The small-signal that comes out from described voltage sensor unit and described current sensor unit, be sent to current/voltage multiplier 12 input ends of metering input mutually of one among A, B, the C of three-phase electric energy chip respectively, simultaneously other two-phases also are input to the input end of the current/voltage multiplier 12 of metering input, obtain electrical energy pulse output by multiplier 12 and time integral, data are sent to central processor unit 4 by SPI interface 13.Described central processor unit 4 is processed as data processing and satisfies various data and the curve that electric energy meter 6 requires.But the electric energy chip inside for the current transformer unit 3 of sieve Paderewski air core coil formula has current integrator 11, can be sending into multiplier 12 metering electric energy after the differential signal reduction again.
After comparing with existing technical scheme, useful effect of the present utility model is: with respect to High-voltage measuring box (cabinet), the high-voltage electric-energy meter volume in the technical solutions of the utility model is small and exquisite, in light weight; Survey the high-voltage electric energy meter of company with respect to Wuhan state, the high-voltage electric energy meter in the technical solutions of the utility model is operated in low-pressure side, and simplicity of design, reliability height are with low cost.
Above content be in conjunction with concrete preferred implementation to further describing that the utility model is done, can not assert that concrete enforcement of the present utility model is confined to these explanations.For the utility model person of an ordinary skill in the technical field, under the prerequisite that does not break away from the utility model design, can also make some deduction or replace, all should be considered as belonging to protection domain of the present utility model.