CN202854227U - Three-phase three-wire electric parameter acquisition device - Google Patents

Abstract

The utility model discloses a three-phase three-wire electric parameter acquisition device, which comprises a parameter acquisition circuit, a current sampling circuit and a microprocessor. The current sampling circuit acquires a current of a phase A, and the parameter acquisition circuit acquires a line voltage between a phase B and a phase C simultaneously. The parameter acquisition circuit and the microprocessor are in bidirectional communication with each other. According to the technical scheme of the utility model, the three-phase three-wire electric parameter acquisition device acquires the current of the phase A and the voltage between the phase B and the phase C and then transmits obtained signals to a chip CS5460A used specially for acquiring electric parameters, so that a power factor can be figured out. Meanwhile, the device is accurate in sampling and has no influence on the calculation of the power factor.

Description

Phase three-wire three electric parameter acquisition device

Technical field

The utility model relates to a kind of phase three-wire three electric parameter acquisition device.

Background technology

Reactive-load compensation is generally used in electric system, in the phase three-wire three electric system, traditional power factor acquisition scheme is the logical angle that gathers between BC phase voltage and the A phase current, constantly calculates the power factor of current electrical network with the current zero-crossing point mistiming constantly by voltage zero-cross.The more than ten years in the past at that time in the electrical network voltage and current harmonic content lower, this scheme can accurately gather the power factor of electrical network, normally realizes reactive-load compensation, guarantees that power factor after the compensation is in the scope that power administration allows.

But along with the in recent years use of a large amount of copped wave equipment, switch power supply equipment, cause harmonic source to increase, voltage harmonic and current harmonic content are higher, and above-mentioned power factor acquisition scheme the inaccurate situation of sampling can occur under such occasion.Affect the normal operation of reactive compensation system, even the situation of being imposed a fine by power administration can occur.

Present chip production both domestic and external producer has released special-purpose electric parameter acquisition chip successively, and this chip can accurately gather electrical network parameter under the larger occasion of voltage harmonic and current harmonics.But this class chip is difficult to use in the system of phase three-wire three all for single-phase.

The utility model content

The utility model purpose is to provide a kind of phase three-wire three electric parameter acquisition device for the defective that prior art exists.

The utility model adopts following technical scheme for achieving the above object:

The utility model phase three-wire three electric parameter acquisition device, comprise parameter acquisition circuit, current sampling circuit and microprocessor, current sampling circuit gathers the A phase current, and the parameter acquisition circuit gathers line voltage, parameter acquisition circuit and the microprocessor two-way communication between B phase and the C phase simultaneously.

It is the acquisition chip of CS5460A that described parameter acquisition circuit adopts model.

Described current sampling circuit is the current sample inductance.

The utility model is delivered to this signal among the special-purpose acquisition chip CS5460A of parameters of electric power by gathering BC phase voltage and A phase current, comes the rated output factor, and sampling does not precisely affect the calculating of power factor.

Description of drawings

Fig. 1: the utility model structural representation.

Embodiment

As shown in Figure 1, the utility model phase three-wire three electric parameter acquisition device, comprise parameter acquisition circuit, current sampling circuit and microprocessor, current sampling circuit gathers the A phase current, the parameter acquisition circuit gathers line voltage, parameter acquisition circuit and the microprocessor two-way communication between B phase and the C phase simultaneously.

It is the acquisition chip of CS5460A that described parameter acquisition circuit adopts model.

Described current sampling circuit is the current sample inductance.

A line voltage and a phase current of gathering on the circuit come voltage, electric current, active power, reactive power and power factor to circuit to calculate.The effective value of voltage and current carries out hardware by CS5460 and calculates.Voltage and current at circuit all is that the reactive power of system is in the situation of three-phase symmetrical

Q=3U _aI _asinφ

Wherein φ is power-factor angle.Again because

Ratio

Leading 900, amplitude differs

Doubly, so can get

By following formula as can be known, as long as gather U _CbAnd I _a, and they are sent in the CS5460, calculate according to the method for active power, multiply by again Just obtain the reactive power of actual track.

Reactive power has been arranged, and the active power that just can obtain system is:

$P=\sqrt{S^2-Q^2}=\sqrt{U^2{I}^2-Q^2}$

Power factor is:

$\cos \mathrm{\φ}=\frac{P}{S}=\frac{P}{\mathrm{UI}}$

The positive and negative of φ angle judged by the positive and negative of reactive power, when Q＞0, and φ〉0, load is perception; When Q＜0, φ＜0, load is capacitive.

Claims (3)

1. phase three-wire three electric parameter acquisition device, it is characterized in that comprising parameter acquisition circuit, current sampling circuit and microprocessor, current sampling circuit gathers the A phase current, and the parameter acquisition circuit gathers line voltage, parameter acquisition circuit and the microprocessor two-way communication between B phase and the C phase simultaneously.

2. phase three-wire three electric parameter acquisition device according to claim 1 is characterized in that it is the acquisition chip of CS5460A that described parameter acquisition circuit adopts model.

3. phase three-wire three electric parameter acquisition device according to claim 1 is characterized in that described current sampling circuit is the current sample inductance.

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