CN111537809A - Digital phase sequence detection method suitable for alternating current power supply system - Google Patents
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Abstract
The invention provides a digital phase sequence detection method suitable for an alternating current power supply system, which comprises the steps of firstly, carrying out CLARKE conversion on a three-phase alternating current voltage signal obtained by sampling, and converting the three-phase alternating current voltage signal into a voltage signal in a two-phase static coordinate system; secondly, passing the alpha-axis voltage signal and the beta-axis voltage signal in the two-phase static coordinate system through a frequency self-adaptive low-pass filter to obtain voltage signals with the time delay of 1/4 periods; then, the voltage signals of the alpha axis and the beta axis at the current moment and the corresponding voltage signals obtained after 1/4 cycle delay are utilized to decompose the alpha axis and the beta axis into positive and negative sequence voltage components of the alpha axis and the beta axis; respectively calculating the amplitudes of the positive sequence voltage and the negative sequence voltage according to the alpha-axis positive sequence voltage component and the beta-axis negative sequence voltage component obtained by decomposition; finally, comparing the positive sequence voltage amplitude and the negative sequence voltage amplitude to judge the phase sequence of the three-phase alternating-current voltage; if the amplitude of the positive sequence voltage is larger than that of the negative sequence voltage, the phase sequence of the three-phase alternating current voltage is represented as a positive sequence; otherwise, it indicates that the phase sequence of the three-phase ac voltage is a negative sequence. The invention can improve the reliability of the phase sequence detection result.
Description
Technical Field
The invention belongs to the field of control and protection of an airplane power supply system, is used for judging a three-phase alternating current phase sequence in an alternating current power supply system, and relates to a digital phase sequence detection method based on a frequency self-adaptive voltage positive and negative sequence component decomposition algorithm.
Background
The phase sequence is an important performance index of the three-phase alternating current power supply, if the phase sequence is incorrect, the failure of electric equipment is caused if the phase sequence is light, and the flight safety accident can be caused by serious people. Therefore, phase sequence protection is a basic protection function in an aircraft alternating current power supply system. The power frequency of the variable frequency alternating current power supply system changes in a large range (for example, the frequency range of the narrow variable frequency alternating current power supply system is about 360Hz-540Hz, and the frequency range of the wide variable frequency power supply system can reach 360Hz-800Hz), so that the difficulty of phase sequence detection is obviously increased.
The traditional phase sequence judging method mainly utilizes the characteristic that the phases of three-phase voltages are different by 120 degrees, each phase voltage signal is converted into a pulse, and the sequence of the three pulse signals is judged by adopting a zero-crossing comparison method. The method has the defect that when the waveform distortion is serious due to high harmonic and high-frequency interference content in the voltage, the result of phase sequence judgment is influenced, and even misjudgment is caused.
Chinese patent publication No. CN 106872808B: a phase sequence self-adaptive three-phase voltage phase-locked loop algorithm needs to use a phase-locked loop and calculate a phase angle according to a rotation frequency error and a standby and running sampling time interval to judge a phase sequence. Chinese patent publication No. CN 101320063B: the phase sequence direction of the three-phase alternating current can be judged only after the angular frequency is calculated through closed-loop control. Chinese patent publication No. CN 105259429B: a three-phase electric phase sequence judging method judges the phase sequence by rotating coordinate transformation according to the quadrants of the voltage vectors of the current period and the last period and the relative relation thereof and setting auxiliary conditions. Chinese patent publication No. CN 104459354A: a method and a device for detecting the phase sequence of a three-phase alternating current network are disclosed, which firstly carry out the decomposition of positive and negative sequence components in a three-phase coordinate system, and then judge the phase sequence of three-phase voltage by rotating coordinate transformation and comparing the amplitudes of the positive and negative sequence components. The above method has the disadvantages of complex principle and difficult realization; in addition, the situation that the frequency of the voltage signal changes rapidly in a wide range is not considered, and the result reliability is low when the voltage signal is applied to a variable-frequency alternating-current power supply system.
Disclosure of Invention
The invention provides a digital phase sequence detection method based on a frequency self-adaptive voltage positive sequence component decomposition algorithm, which can be used for an airplane variable-frequency alternating current power supply system, so as to improve the reliability of a phase sequence detection result and simplify the realization of the phase sequence detection function.
The technical scheme of the invention is as follows:
the digital phase sequence detection method suitable for the alternating current power supply system is characterized by comprising the following steps of: the method comprises the following steps:
step 1: carrying out CLARKE conversion on a three-phase alternating voltage signal sampled by an alternating current power supply system, and converting the three-phase alternating voltage signal into a voltage signal in a two-phase static coordinate system;
step 2: passing the alpha-axis voltage signal and the beta-axis voltage signal in the two-phase static coordinate system through a frequency self-adaptive low-pass filter to obtain voltage signals with the time delay of 1/4 periods;
and step 3: decomposing the alpha axis and beta axis voltages into alpha axis and beta axis positive and negative sequence voltage components by using the current alpha axis and beta axis voltage signals and corresponding voltage signals obtained through 1/4 cycle delay;
and 4, step 4: respectively calculating the amplitudes of the positive sequence voltage and the negative sequence voltage according to the alpha-axis positive sequence voltage component and the beta-axis negative sequence voltage component obtained by decomposition;
and 5: comparing the positive sequence voltage amplitude and the negative sequence voltage amplitude to judge the phase sequence of the three-phase alternating-current voltage; if the amplitude of the positive sequence voltage is larger than that of the negative sequence voltage, the phase sequence of the three-phase alternating current voltage is represented as a positive sequence; otherwise, it indicates that the phase sequence of the three-phase ac voltage is a negative sequence.
Further, in step 1, when the phase voltage contains a zero sequence component, the line voltage is used for phase sequence judgment.
Further, in step 1, the process of performing CLARKE transformation on the three-phase alternating voltage signal and converting the three-phase alternating voltage signal into a voltage signal in a two-phase stationary coordinate system is as follows:
wherein v isa、vb、vcRepresenting three-phase voltage signals, v, respectivelyαAnd vβRepresenting the α and β axis components of the voltage, respectively.
Further, a frequency-adaptive second-order low-pass filter is adopted in step 2, and a transfer function of an s domain of the frequency-adaptive second-order low-pass filter is as follows:
wherein ω isvfExpressing the frequency of the variable-frequency alternating-current power supply, and discretizing a transfer function of an s domain to obtain:
wherein T issRepresenting the sampling period.
Further, in step 2, the discretized transfer function is expressed as
Wherein:
d2＝1
order:
to obtain
n0＝a1/a2
n1＝2n0
n2＝n0
d0＝(a1-4a0+4)/a2
d1＝2(a1-4)/a2。
Further, in step 3, the α -axis and β -axis voltages are decomposed into α -axis and β -axis positive and negative sequence voltage components according to the following formula:
wherein v isαp、vβp、vαn、vβnRepresenting positive and negative sequence components, v, of α -axis and β -axis voltages, respectivelyα(t) and vβ(t) respectively represent the current timesInstantaneous components of voltage of α axis and β axis, T represents period of AC voltage signal, vα(T-T/4) and vβ(T-T/4) each represents vα(t) and vβ(t) delaying the signal obtained by 1/4 cycles respectively.
Further, in step 4, according to the α -axis and β -axis positive and negative sequence voltage components obtained by decomposition, the amplitudes of the positive and negative sequence voltages are respectively calculated as:
wherein A ispmAnd AnmRepresenting the magnitude of the positive and negative sequence voltages, respectively.
Advantageous effects
Compared with the hardware detection technology, the invention can reduce the complexity of the hardware circuit and save the cost of phase sequence detection. Compared with the existing digital phase sequence judgment method, the method has the advantages that the principle and the realization are simple, the rotation coordinate transformation is not needed, and the phase sequence judgment can be realized only by comparing the magnitudes of the positive sequence component and the negative sequence component. Moreover, the invention has strong applicability, and can be applied to a variable-frequency alternating-current power supply system and a constant-frequency alternating-current power supply system.
Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
Drawings
The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
fig. 1 is a schematic diagram of a proposed digital phase sequence detection method suitable for a variable frequency ac power supply system.
FIG. 2 shows the results of the detection of a three-phase voltage balance, positive sequence, with phase A at an initial phase angle of 30 DEG and a frequency rising from 350Hz to 390Hz at a rate of 400 Hz/s.Wherein A ispmAnd AnmThe amplitudes of the positive sequence voltage and the negative sequence voltage are respectively shown (the same below), and the amplitudes of the three-phase voltages are all 162.6V.
FIG. 3 shows the results of a three-phase voltage balance, negative sequence, with phase A at an initial phase angle of 90 ° and a frequency decreasing from 810Hz to 790Hz at a rate of-400 Hz/s.
FIG. 4 shows the detection results of the phase-missing and positive sequence of phase B, phase A having an initial phase angle of 90 deg., and a frequency decreasing from 390Hz to 350Hz at a rate of-400 Hz/s.
FIG. 5 shows the detection results of phase-missing and negative sequence of phase B, phase A having an initial phase angle of-60 deg., and a frequency rising from 790Hz to 810Hz at a rate of 400 Hz/s.
Detailed Description
The following detailed description of embodiments of the invention is intended to be illustrative, and not restrictive, of the invention.
The embodiment provides a digital phase sequence detection method suitable for a variable frequency alternating current power supply system. The method is realized in a two-phase static coordinate system, and the phase sequence of the three-phase alternating-current voltage can be judged only by judging the magnitude of the positive-sequence voltage amplitude and the negative-sequence voltage amplitude. The method is suitable for a three-phase variable frequency alternating current power supply system and a three-phase constant frequency alternating current power supply system. The steps of the method are shown in fig. 1, and the specific operation process is as follows:
the method comprises the following steps: the three-phase AC voltage signal obtained by sampling is converted into a two-phase static coordinate system by using CLARKE conversion (assuming that the phase voltage does not contain zero-sequence component)
The transformation relation from the three-phase static coordinate system to the two-phase static coordinate system is as follows:
wherein v isa、vb、vcRepresenting three-phase voltage signals, v, respectivelyαAnd vβRepresenting the α and β axis components of the voltage, respectively.
Step two: and respectively obtaining voltage signals with the time delay of 1/4 periods by applying a frequency self-adaptive second-order low-pass filter method to the alpha-axis voltage signals and the beta-axis voltage signals obtained by conversion:
the transfer function of the s-domain of the frequency adaptive second-order low-pass filter is shown as the formula (2).
Wherein, ω isvfThe frequency (rad/s) of the variable frequency ac power source is shown.
Discretizing the formula (2) can obtain:
wherein, TsRepresenting the sampling period.
H is to bea(z) is expressed in the concise form as follows:
wherein:
d2＝1 (10)
for convenience of calculation, let:
the following can be obtained:
n0＝a1/a2(11)
n1＝2n0(12)
n2＝n0(13)
d0＝(a1-4a0+4)/a2(14)
d1＝2(a1-4)/a2(15)
step three: the voltage signals of the alpha axis and the beta axis at the current moment and the corresponding voltage signals obtained after 1/4 cycle delay are utilized to decompose the alpha axis and the beta axis into corresponding positive and negative sequence voltage components
In the two-phase stationary coordinate system, the positive and negative sequence components of the voltage can be respectively expressed as:
wherein v isαp、vβp、vαn、vβnRepresenting positive and negative sequence components, v, of α -axis and β -axis voltages, respectivelyα(t) and vβ(T) represents instantaneous components of the voltage of α axes and β axes at the present time, respectively, T represents the period of the AC voltage signal, v representsα(T-T/4) and vβ(T-T/4) each represents vα(t) and vβ(t) delaying the signals obtained by 1/4 periods respectivelyNumber (n).
Fourthly, according to the α axis and β axis positive and negative sequence voltage components v obtained by decompositionαp、vβp、vαnAnd vβnRespectively calculating the amplitudes of the positive and negative sequence voltages
Let α -axis and β -axis positive and negative sequence voltages be expressed as:
wherein A ispmAnd AnmRepresenting the magnitude of the positive and negative sequence voltages respectively,
and
representing the initial phase angles of the positive and negative sequence voltages, respectively.
The magnitudes of the positive and negative sequence voltages can be calculated as:
step five: judging the phase sequence of three-phase AC voltage by comparing the magnitude of the positive and negative sequence voltage amplitudes
If the amplitude of the positive sequence voltage is larger than that of the negative sequence voltage, the phase sequence of the three-phase voltage is represented as a positive sequence; otherwise, the phase sequence representing the three-phase voltage is a negative sequence.
Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made in the above embodiments by those of ordinary skill in the art without departing from the principle and spirit of the present invention.
Claims (7)
1. A digital phase sequence detection method suitable for an alternating current power supply system is characterized by comprising the following steps: the method comprises the following steps:
step 1: carrying out CLARKE conversion on a three-phase alternating voltage signal sampled by an alternating current power supply system, and converting the three-phase alternating voltage signal into a voltage signal in a two-phase static coordinate system;
step 2: passing the alpha-axis voltage signal and the beta-axis voltage signal in the two-phase static coordinate system through a frequency self-adaptive low-pass filter to obtain voltage signals with the time delay of 1/4 periods;
and step 3: decomposing the alpha axis and beta axis voltages into alpha axis and beta axis positive and negative sequence voltage components by using the current alpha axis and beta axis voltage signals and corresponding voltage signals obtained through 1/4 cycle delay;
and 4, step 4: respectively calculating the amplitudes of the positive sequence voltage and the negative sequence voltage according to the alpha-axis positive sequence voltage component and the beta-axis negative sequence voltage component obtained by decomposition;
and 5: comparing the positive sequence voltage amplitude and the negative sequence voltage amplitude to judge the phase sequence of the three-phase alternating-current voltage; if the amplitude of the positive sequence voltage is larger than that of the negative sequence voltage, the phase sequence of the three-phase alternating current voltage is represented as a positive sequence; otherwise, it indicates that the phase sequence of the three-phase ac voltage is a negative sequence.
2. The digital phase sequence detection method suitable for the alternating current power supply system according to claim 1, characterized in that: in step 1, when the phase voltage contains a zero sequence component, the line voltage is used for judging the phase sequence.
3. The digital phase sequence detection method suitable for the alternating current power supply system according to claim 1, characterized in that: in step 1, the process of carrying out CLARKE conversion on the three-phase alternating current voltage signal and converting the three-phase alternating current voltage signal into a voltage signal in a two-phase static coordinate system comprises the following steps:
wherein v isa、vb、vcRepresenting three-phase voltage signals, v, respectivelyαAnd vβRepresenting the α and β axis components of the voltage, respectively.
4. The digital phase sequence detection method suitable for the alternating current power supply system according to claim 1, characterized in that: in step 2, a frequency-adaptive second-order low-pass filter is adopted, and the transfer function of the s domain of the frequency-adaptive second-order low-pass filter is as follows:
wherein ω isvfExpressing the frequency of the variable-frequency alternating-current power supply, and discretizing a transfer function of an s domain to obtain:
wherein T issRepresenting the sampling period.
5. The digital phase sequence detection method suitable for the alternating current power supply system according to claim 4, wherein: in step 2, the discretized transfer function is expressed as
Wherein:
d2＝1
order:
to obtain
n0＝a1/a2
n1＝2n0
n2＝n0
d0＝(a1-4a0+4)/a2
d1＝2(a1-4)/a2。
6. The digital phase sequence detection method suitable for the alternating current power supply system according to claim 1, characterized in that: in step 3, the alpha axis and beta axis voltages are decomposed into alpha axis and beta axis positive and negative sequence voltage component formulas as follows:
wherein v isαp、vβp、vαn、vβnRepresenting positive and negative sequence components, v, of α -axis and β -axis voltages, respectivelyα(t) and vβ(T) represents instantaneous components of the voltage of α axes and β axes at the present time, respectively, T represents the period of the AC voltage signal, v representsα(T-T/4) and vβ(T-T/4) each represents vα(t) and vβ(t) delaying the signal obtained by 1/4 cycles respectively.
7. The digital phase sequence detection method suitable for the alternating current power supply system according to claim 6, wherein: in step 4, according to the alpha axis and beta axis positive and negative sequence voltage components obtained by decomposition, the amplitudes of the positive and negative sequence voltages are respectively calculated as follows:
wherein A ispmAnd AnmRepresenting the magnitude of the positive and negative sequence voltages, respectively.
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Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102243277A (en) * | 2011-04-14 | 2011-11-16 | 国电南瑞科技股份有限公司 | Method for detecting positive sequence quantity and negative sequence quantity of rotor voltage of double-feed wind power generator under double synchronous reference frames (SRF) |
| CN102680806A (en) * | 2012-04-20 | 2012-09-19 | 京东方科技集团股份有限公司 | Detection method and detection device for three-phase alternating-current phase sequence |
| CN103117544A (en) * | 2013-02-27 | 2013-05-22 | 四川科陆新能电气有限公司 | Method and device for separating positive sequence component and negative sequence component of network voltage or current |
| CN104218573A (en) * | 2014-08-29 | 2014-12-17 | 华南理工大学 | Control method of MMC-HVDC (multi media card-high voltage direct current) during power grid malfunction of receiving end |
| CN104459354A (en) * | 2013-09-22 | 2015-03-25 | 阳光电源股份有限公司 | Three-phase alternating-current network phase sequence detection method and device |
| CN105162137A (en) * | 2015-09-12 | 2015-12-16 | 南昌航空大学 | Reactive and harmonic current detection algorithm in complex power network |
| CN105259429A (en) * | 2015-10-30 | 2016-01-20 | 厦门科华恒盛股份有限公司 | Three-phase electricity phase sequence judging method |
| JP2017133914A (en) * | 2016-01-27 | 2017-08-03 | 日置電機株式会社 | Measurement device |
| CN107706929A (en) * | 2016-07-26 | 2018-02-16 | 南京工程学院 | Adaptive phase locked loop method and system based on minimum variance filtering |
| CN108226588A (en) * | 2017-11-01 | 2018-06-29 | 中国矿业大学(北京) | It is a kind of to be suitable for single-phase and three-phase electrical power system Method of Software Phase Lock |
| CN109659983A (en) * | 2018-11-26 | 2019-04-19 | 合肥科威尔电源系统有限公司 | Software phase-lock loop implementation method and device based on IDFT |
| CN110011312A (en) * | 2019-05-27 | 2019-07-12 | 河北交通职业技术学院 | Frequency adaptive phase locked loop modeling method based on internal model |
-
2020
- 2020-06-21 CN CN202010570236.4A patent/CN111537809B/en active Active
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102243277A (en) * | 2011-04-14 | 2011-11-16 | 国电南瑞科技股份有限公司 | Method for detecting positive sequence quantity and negative sequence quantity of rotor voltage of double-feed wind power generator under double synchronous reference frames (SRF) |
| CN102680806A (en) * | 2012-04-20 | 2012-09-19 | 京东方科技集团股份有限公司 | Detection method and detection device for three-phase alternating-current phase sequence |
| CN103117544A (en) * | 2013-02-27 | 2013-05-22 | 四川科陆新能电气有限公司 | Method and device for separating positive sequence component and negative sequence component of network voltage or current |
| CN104459354A (en) * | 2013-09-22 | 2015-03-25 | 阳光电源股份有限公司 | Three-phase alternating-current network phase sequence detection method and device |
| CN104218573A (en) * | 2014-08-29 | 2014-12-17 | 华南理工大学 | Control method of MMC-HVDC (multi media card-high voltage direct current) during power grid malfunction of receiving end |
| CN105162137A (en) * | 2015-09-12 | 2015-12-16 | 南昌航空大学 | Reactive and harmonic current detection algorithm in complex power network |
| CN105259429A (en) * | 2015-10-30 | 2016-01-20 | 厦门科华恒盛股份有限公司 | Three-phase electricity phase sequence judging method |
| JP2017133914A (en) * | 2016-01-27 | 2017-08-03 | 日置電機株式会社 | Measurement device |
| CN107706929A (en) * | 2016-07-26 | 2018-02-16 | 南京工程学院 | Adaptive phase locked loop method and system based on minimum variance filtering |
| CN108226588A (en) * | 2017-11-01 | 2018-06-29 | 中国矿业大学(北京) | It is a kind of to be suitable for single-phase and three-phase electrical power system Method of Software Phase Lock |
| CN109659983A (en) * | 2018-11-26 | 2019-04-19 | 合肥科威尔电源系统有限公司 | Software phase-lock loop implementation method and device based on IDFT |
| CN110011312A (en) * | 2019-05-27 | 2019-07-12 | 河北交通职业技术学院 | Frequency adaptive phase locked loop modeling method based on internal model |
Non-Patent Citations (1)
| Title |
|---|
| 吉正华 等: "基于dq变换的三相软件锁相环设计", 《电力自动化设备》 * |
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