CN203104409U

CN203104409U - Digital phase-locked loop tracking system used for accurately detecting commercial power

Info

Publication number: CN203104409U
Application number: CN 201220731024
Authority: CN
Inventors: 孙宏宇
Original assignee: SHIJIAZHUANG TONHE ELECTRONICS TECHNOLOGIES Co Ltd
Current assignee: SHIJIAZHUANG TONHE ELECTRONICS TECHNOLOGIES Co Ltd
Priority date: 2012-12-26
Filing date: 2012-12-26
Publication date: 2013-07-31
Anticipated expiration: 2022-12-26

Abstract

The utility model provides a digital phase-locked loop tracking system used for accurately detecting the commercial power, which comprises a zero-crossing comparator used for reshaping an analog signal obtained through sampling the commercial power and transforming the signal of the commercial power into a square-wave signal of the same frequency and the same phase as the commercial power through a distorted sine wave, an edge detector used for detecting the rising or falling edge of the square-wave signal so as to calculate the cycle and the frequency of input signals, three digital filters, an N divider, an A/D sampler, and a signal mathematical processor used for processing A/D sampling signals. The low-pass filtering operation is enabled through the three digital filters, the N divider and the A/D sampler. Both the zero-crossing comparator and the A/D sampler are connected with input signals. The zero-crossing comparator is connected sequentially with the edge detector, the first digital filter, the N divider, the N divider, the A/D sampler, the signal mathematical processor and the third digital filter. According to the utility model, the hardware circuit of the digital phase-locked loop tracking system used for accurately detecting the commercial power is simplified and the cost thereof is lowered. Meanwhile, the phase-locking speed is improved.

Description

A kind of civil power accurately detects the phase-locked system of numeral that follows the tracks of

Technical field

The utility model relates to a kind of digital lock-in technique field that civil power phase place, frequency accurately detect, follow the tracks of, and particularly relates to a kind of civil power and accurately detects the phase-locked system of numeral that follows the tracks of.

Background technology

At multiple application (for example UPS, photovoltaic/wind energy combining inverter etc.), need detect the phase of civil power, follow the tracks of.Usually the civil power phase/frequency detection all adopts the zero crossing detection method, promptly detects the zero crossing of civil power by a comparator, obtains the cycle and the frequency of civil power then by the time interval between the adjacent zero crossing before and after calculating.Obtain the cycle and the frequency of inverter voltage with method, carry out closed-loop control, regulate the frequency and the phase place of inverter voltage, make inversion output and civil power with the frequency homophase according to difference on the frequency, the phase information of line voltage and inverter voltage.

Wherein, phase-locked principle is carried out phase calculation and frequency computation part to line voltage as shown in Figure 1, and inverter voltage also carried out phase calculation and frequency computation part.Then the phase calculation output of line voltage and inverter voltage is carried out outputing to phase-locked controller after the computing; The frequency computation part output of line voltage and inverter voltage is carried out outputing to the frequency-tracking controller after the computing; The output of phase-locked then controller and frequency-tracking controller is carried out exporting the inversion phase control after the computing.

The circuit of this structure have principle simply, advantage clearly, but hardware circuit is complicated, and the same circuit of two covers need be set simultaneously, respectively line voltage and inverter voltage is detected simultaneously.

The utility model content

The technical problems to be solved in the utility model provide the simple cost of a kind of circuit structure low, can carry out the civil power that zero crossing detect to judge to civil power and accurately detect the phase-locked system of numeral that follows the tracks of.

For solving the problems of the technologies described above, embodiment of the present utility model provides a kind of civil power accurately to detect and follows the tracks of the phase-locked system of numeral, comprise be used for analog signal that civil power sampling obtains carry out shaping and with city's signal of telecommunication by the sine wave of a distortion transform into one with civil power with the zero-crossing comparator of the square-wave signal of homophase frequently, be used to detect the rising edge of square-wave signal or trailing edge with the cycle of calculating input signal and the marginal detector of frequency, be used to realize three digital filters of low-pass filtering, the N divider, the A/D sampler is used for the signal mathematics processor that the A/D sampled signal is handled; Wherein zero-crossing comparator all is connected input signal with the A/D sampler, and zero-crossing comparator connects marginal detector, first digital filter, N divider, A/D sampler, signal mathematics processor, the 3rd digital filter successively.

The beneficial effect of technique scheme of the present utility model is as follows:

Civil power of the present utility model has accurately detected the hardware circuit of having followed the tracks of the phase-locked system simplification of numeral, has reduced cost, and has improved phase-locked speed.

Description of drawings

Fig. 1 is existing phase-locked schematic diagram;

Fig. 2 is the structural representation of the utility model embodiment.

Embodiment

For making the technical problems to be solved in the utility model, technical scheme and advantage clearer, be described in detail below in conjunction with the accompanying drawings and the specific embodiments.

Embodiment of the present utility model provides a kind of civil power as shown in Figure 2 accurately to detect and follows the tracks of the phase-locked system of numeral, comprise: be used for analog signal that civil power sampling obtains carry out shaping and with city's signal of telecommunication by the sine wave of a distortion transform into one with civil power with the zero-crossing comparator of the square-wave signal of homophase frequently, be used to detect the rising edge of described square-wave signal or trailing edge with the cycle of calculating input signal and the marginal detector of frequency, be used to realize low-pass filtering first digital filter, second digital filter, the 3rd digital filter is used to adjust the N divider of A/D sample frequency, the A/D sampler, be used for signal mathematics processor that the A/D sampled signal is handled; Wherein zero-crossing comparator all is connected input signal with the A/D sampler, and zero-crossing comparator connects marginal detector, first digital filter, N divider, A/D sampler, signal mathematics processor, the 3rd digital filter successively.The 3rd digital filter provides output signal.

The zero-crossing comparator analog signal that sampling obtains to civil power is carried out shaping, with city's signal of telecommunication by the sine wave of a distortion transform into one with civil power with the square-wave signal of homophase frequently, marginal detector detects the rising edge of square-wave signal or cycle and the frequency that trailing edge is used to calculate input signal, first digital filter is realized low-pass filtering, the output of N divider is used to adjust the A/D sample frequency, second digital filter is realized low-pass filtering, signal mathematics processing unit performs mathematical calculations to the A/D sampled signal, the 3rd digital filter is realized low-pass filtering, finally reaches the same frequency homophase with input signal.

From the principle of phase lock loop structured flowchart of Fig. 2 as seen, the zero-crossing comparator analog signal that sampling obtains to civil power is carried out shaping, with city's signal of telecommunication by the sine wave of a distortion transform into one with civil power with the square-wave signal of homophase frequently, marginal detector detects the rising edge of square-wave signal or cycle and the frequency that trailing edge is used to calculate input signal, digital filter 1 is realized low-pass filtering, the output of N divider is used to adjust the A/D sample frequency, digital filter 2 is realized low-pass filtering, signal mathematics processing unit performs mathematical calculations to the A/D sampled signal, digital filter 3 is realized low-pass filtering, finally reaches the same frequency homophase with input signal.

Concrete, operation principle of the present utility model is: utilize the current data of the A/D sampled result of input signal, and last one historical data of clapping, just can easily obtain same frequency in-phase signal with input signal.The utility model is not subjected to the influence of input signal distortion and amplitude, and its phase-locked output all is one and imports the standard sine wave output signal of frequency homophase together, can realize the phase-locked function of different frequency civil power, realizes the phase-locked function of 50Hz or 60Hz civil power simply.

The above is a preferred implementation of the present utility model; should be understood that; for those skilled in the art; under the prerequisite that does not break away from principle described in the utility model; can also make some improvements and modifications, these improvements and modifications also should be considered as protection range of the present utility model.

Claims

1. a civil power accurately detects the phase-locked system of numeral that follows the tracks of, it is characterized in that, comprise be used for analog signal that civil power sampling obtains carry out shaping and with city's signal of telecommunication by the sine wave of a distortion transform into one with civil power with the zero-crossing comparator of the square-wave signal of homophase frequently, be used to detect the rising edge of square-wave signal or trailing edge with the cycle of calculating input signal and the marginal detector of frequency, be used to realize three digital filters, N divider, the A/D sampler of low-pass filtering, be used for the signal mathematics processor that the A/D sampled signal is handled; Wherein zero-crossing comparator all is connected input signal with the A/D sampler, and zero-crossing comparator connects marginal detector, first digital filter, N divider, A/D sampler, signal mathematics processor, the 3rd digital filter successively.