Single-phase phase-locked loop and amplitude-frequency two-dimensional tracking control method based on multi-frequency principle

Abstract

The present invention discloses a single-phase phase-locked loop and an amplitude-frequency two-dimensional tracking control method based on the multi-frequency principle, belonging to the field of power systems, comprising: a multi-frequency processing module, used to perform multi-frequency processing on the original signal and then output phase information as a control signal X(t); an error calculation module, used to calculate the amplitude error and phase error of the control phasor relative to the tracking signal, and obtain an amplitude error control signal ΔA y (t) and the phase error control signal Δθ y (t); the projections of the control phasor on the α and β axes are A M (t)sinθ M (t) and A M (t)X(t), the amplitude and phase of the tracking signal are respectively the measured amplitude A M (t) and the measured phase θ M (t); and a tracking control module for filtering out ΔA y (t) and Δθ y The high-frequency component in (t) is used to obtain the amplitude and phase errors of the multi-frequency original signal relative to the tracking signal, and the error is controlled to be zero as the control target. Combined with the initial values ​​of the amplitude and phase, new measured amplitude and measured phase are obtained to achieve instant tracking of the amplitude and phase. The present invention can achieve accurate and fast phase locking function.

Description

Technical Field

[0001] The invention belongs to the field of power systems, and more specifically, relates to a single-phase phase-locked loop and an amplitude-frequency two-dimensional tracking control method based on the multi-frequency principle. Background Art

[0002] Keeping all devices in the system synchronized is the foundation for the stable and reliable operation of the system, and is also an important factor affecting the system's performance. Therefore, for almost all grid-connected devices, especially power electronic equipment, it is necessary to continuously monitor the grid voltage information, including frequency, phase and amplitude, to ensure that the output voltage is in the same frequency and phase as the grid, and to achieve grid synchronization.

[0003] With the large-scale application of power electronic devices such as PWM rectifiers, static VAR generators (SVG), and uninterruptible power supplies (UPS), the phase-locked loop provides the grid phase reference for these devices and is an indispensable part of these devices. According to the different power electronic devices, the power phase-locked loop can be roughly divided into three-phase phase-locked loops and single-phase phase-locked loops. Among them, the single-phase phase-locked loop is mainly used in single-phase power electronic devices such as single-phase grid-connected converters, and has a higher time limit difficulty than the three-phase phase-locked loop.

[0004] At present, there are many implementation schemes of single-phase phase-locked loops, but these existing single-phase phase-locked loop technologies have the following main shortcomings: on the one hand, it is difficult for its loop filter to completely filter out the harmonics of the input signal, which will produce a phase offset in the phase-locked loop output signal, resulting in a phase-locked error; on the other hand, there is also a method of obtaining the input signal cycle and phase information through zero-crossing detection, but this scheme can only be adjusted once in each power frequency cycle, resulting in a long phase-locked delay time, and the superposition of harmonics will affect the detection accuracy, and even cause phase-locking failure. In addition, there is also a way to lock the phase by constructing an orthogonal signal of a single-phase signal, but the specific scheme for constructing an orthogonal signal of a single-phase signal is still under exploration in engineering.

[0005] In general, how to suppress the phase shift of the output signal caused by harmonics and reduce the phase-locking delay time in the actual grid-connected system is an urgent problem to be solved. Summary of the invention

[0006] In view of the defects of the prior art and the need for improvement, the present invention provides a single-phase phase-locked loop and an amplitude-frequency two-dimensional tracking control method based on the multi-frequency principle, aiming to solve the technical problems of single-phase phase-locked loop phase offset and long delay in actual power systems.

[0007] To achieve the above object, according to one aspect of the present invention, a single-phase phase-locked loop based on the multi-frequency principle is provided, comprising: a multi-frequency processing module, an error calculation module and a tracking control module;

[0008] The multi-frequency processing module has a first input terminal for receiving a single-phase original signal U o (t) = A(t)cosθ(t), and its second input terminal is used to receive the measured amplitude A output by the tracking control module M (t), which is used to perform multiple frequency multiplication processing on the original signal and output phase information as the control signal X(t);

[0009] The error calculation module has a first input end connected to the output end of the multi-frequency processing module, and a second input end connected to the output end of the tracking control module, which is used to calculate the amplitude error and phase error of the control phasor relative to the tracking signal to obtain the amplitude error control signal ΔA. y (t) and the phase error control signal Δθ y (t); the projections of the control phasor on the α and β axes are A M (t)sinθ M (t) and A M (t)X(t), the amplitude and phase of the tracking signal are the measured amplitude A output by the tracking control module M (t) and the measured phase θ M (t);

[0010] The tracking control module has an input end connected to the output end of the error calculation module, which is used to filter out the amplitude error control signal ΔA y (t) and the phase error control signal Δθ y The high-frequency components in (t) are obtained, and the amplitude error ΔA(t) and phase error Δθ(t) of the original signal after multiple frequency processing relative to the tracking signal are obtained. The control target is to make the error zero. Combined with the given initial amplitude value and initial phase value, new measured amplitude and measured phase are obtained to achieve real-time tracking of amplitude and phase.

[0011] Further, the error calculation module includes: an amplitude error calculation module and a phase error calculation module, the input ends of the two modules together constitute the input end of the error calculation module, and the output ends of the two modules together constitute the output end of the error calculation module;

[0012] Amplitude error calculation module, used to calculate Calculate the amplitude error of the control phasor relative to the tracking signal to obtain the amplitude error control signal ΔA y (t);

[0013] Phase error calculation module, used to Calculate the phase error of the control phasor relative to the tracking signal, the phase error control signal Δθ y (t).

[0014] In some optional embodiments, the tracking control module includes: an error processing module and a controller module;

[0015] The error processing module, whose input terminal is used as the input terminal of the tracking control module, is used to filter out the amplitude error control signal ΔA y (t) and the phase error control signal Δθ y The high-frequency components in (t) are obtained to obtain the amplitude error ΔA(t) and phase error Δθ(t) of the original signal after multiple frequency processing relative to the tracking signal;

[0016] The controller module has an input end connected to the output end of the error processing module and an output end serving as the output end of the tracking control module. The controller module is used to control the error to zero as a control target, and obtain a new measurement amplitude and measurement phase in combination with a given initial amplitude value and an initial phase value.

[0017] Furthermore, the error processing module includes: an amplitude error processing module and a phase error processing module, the input ends of the two modules together constitute the input end of the error processing module, and the output ends of the two modules together constitute the output end of the error processing module;

[0018] Amplitude error processing module, used to filter out the amplitude error control signal ΔA y The high-frequency component in (t) is obtained, and the amplitude error ΔA(t) of the original signal after multiple frequency processing relative to the tracking signal is obtained;

[0019] Phase error processing module, used to filter out the phase error control signal Δθ y The high-frequency component in (t) is obtained, and the phase error Δθ(t) of the original signal after multiple frequency processing relative to the tracking signal is obtained.

[0020] Further, the amplitude error processing module is a low-pass filter, or the amplitude error processing module is based on Calculate the amplitude error ΔA(t);

[0021] Wherein, m is a positive integer.

[0022] Further, the phase error processing module is a low-pass filter, or the phase error processing module is Calculate the phase error Δθ(t);

[0023] Wherein, m is a positive integer.

[0024] Furthermore, the controller module includes: an amplitude controller and a phase controller, the input ends of the two controllers together constitute the input end of the controller module, and the output ends of the two controllers together constitute the output end of the controller module;

[0025] The amplitude controller is used to obtain a new measurement amplitude after performing PI control on the amplitude error ΔA(t) and combining it with a given initial amplitude value;

[0026] The phase controller is used to perform PI control on the phase error Δθ(t), obtain a new measurement frequency in combination with a given frequency initial value, and obtain a new measurement phase in combination with a given phase initial value after integrating the new measurement frequency.

[0027] In some optional implementations, the tracking control module includes: an amplitude pre-compensation module, an amplitude tracking module, a phase error processing module and a phase controller; the input ends of the amplitude pre-compensation module and the phase error processing module together constitute the input end of the tracking control module, the input end of the amplitude tracking module is connected to the output end of the amplitude pre-compensation module, the input end of the phase controller is connected to the output end of the phase error processing module, and the output end of the amplitude tracking module and the output end of the phase processor together constitute the output end of the tracking control module;

[0028] Amplitude pre-compensation module, using amplitude error control signal ΔA y (t) for the measured amplitude A M (t) is compensated to obtain the signal S′=ΔA y (t)+A M (t);

[0029] Amplitude tracking module, used to filter out high-order harmonics in signal S′ and obtain a new measurement amplitude;

[0030] Phase error processing module, used to filter out the phase error control signal Δθ y The high-frequency component in (t) is obtained, and the phase error Δθ(t) of the original signal after multiple frequency processing relative to the tracking signal is obtained;

[0031] The phase controller is used to perform PI control on the phase error Δθ(t), obtain a new measurement frequency in combination with a given frequency initial value, and obtain a new measurement phase in combination with a given phase initial value after integrating the new measurement frequency.

[0032] Furthermore, the calculation expression of the control signal obtained by the multiple frequency processing module (1) performing multiple frequency processing on the original signal is:

[0033]

[0034] in, n represents the frequency doubling times, and n>1.

[0035] According to another aspect of the present invention, there is provided an amplitude-frequency two-dimensional tracking control method based on the multi-frequency principle, comprising:

[0036] The received single-phase original signal U o (t) = A(t)cosθ(t) after multiple frequency processing, the output phase information is used as the control signal X(t);

[0037] Calculate the amplitude error and phase error of the control phasor relative to the tracking signal to obtain the amplitude error control signal ΔA y (t) and the phase error control signal Δθ y (t); the projections of the control phasor on the α and β axes are A M (t)sinθ M (t) and A M (t)X(t), the amplitude and phase of the tracking signal are respectively the measured amplitude A of the feedback input M (t) and the measured phase θ M (t);

[0038] Filter the amplitude error control signal ΔA y (t) and the phase error control signal Δθ y The high-frequency components in (t) are obtained, and the amplitude error ΔA(t) and phase error Δθ(t) of the original signal after multiple frequency processing relative to the tracking signal are obtained. The control target is to make the error zero. Combined with the given initial amplitude value and initial phase value, new measured amplitude and measured phase are obtained to achieve real-time tracking of amplitude and phase.

[0039] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects:

[0040] (1) The present invention performs phase locking after frequency doubling the original signal. On the one hand, since the difference between the harmonics and the fundamental frequency in the original signal increases after the frequency doubling process, it is easy to accurately filter out the harmonics, thereby effectively suppressing the output signal phase offset problem caused by harmonics in the traditional phase-locked loop and improving the detection accuracy of the phase-locked loop; on the other hand, after the frequency doubling process, the phase-locking period is correspondingly shortened, so the phase-locking delay time can be reduced in the actual grid-connected system. In general, the present invention can achieve a fast and accurate phase-locking function.

[0041] (2) After the control signal X(t) is obtained by frequency multiplication, the present invention combines the measured amplitude A M (t) and the measured phase θ M (t) constructing a control phasor and controlling the error between the control phasor and the tracking signal so that when the control phasor completely tracks the measured tracking phasor, the control phasor, the tracking signal and the actual original signal can completely coincide with each other, thereby realizing the phase-locking function when the amplitude, frequency and phase information of the phasor corresponding to the original signal cannot be directly measured.

[0042] (3) In the single-phase phase-locked loop provided by the present invention, each functional module can be implemented using existing modules, and there are multiple alternative implementation schemes, which can be easily applied in engineering. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 A schematic diagram of a single-phase phase-locked loop structure based on the multi-frequency principle provided by an embodiment of the present invention;

[0044] Figure 2 A structural block diagram of a multiple frequency processing module provided by an embodiment of the present invention;

[0045] Figure 3 A schematic diagram of a control phasor structure provided by an embodiment of the present invention;

[0046] Figure 4 A structural block diagram of an amplitude error calculation module provided by an embodiment of the present invention;

[0047] Figure 5 A structural block diagram of a phase error calculation module provided by an embodiment of the present invention;

[0048] Figure 6 One of the structural block diagrams of the amplitude / phase error processing module provided by one embodiment of the present invention;

[0049] Figure 7 A second structural block diagram of an amplitude / phase error processing module provided by an embodiment of the present invention;

[0050] Figure 8 A structural block diagram of an amplitude controller module provided by an embodiment of the present invention;

[0051] Fig. 9 A block diagram of the phase controller module provided by an embodiment of the present invention;

[0052] Fig.10 A structural block diagram of a direct amplitude measurement provided by an embodiment of the present invention;

[0053] Fig.11 A two-dimensional amplitude-frequency tracking control method based on the multi-frequency principle provided by an embodiment of the present invention;

[0054] In all drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0055] 1 indicates the frequency multiplication processing module;

[0056] 11 represents a multiplier and divider, 12 represents a power generator, 13 represents an amplifier, and 14 represents an adder and subtractor;

[0057] 2 represents the error calculation module;

[0058] 21 represents an amplitude error calculation module, 22 represents a phase error calculation module;

[0059] 21_1 represents a sine generator, 21_2 represents a multiplier, 21_3 represents a square generator, 21_4 represents an adder, 21_5 represents a square root generator, and 21_6 represents an adder-subtractor;

[0060] 22_1 represents a sine generator, 22_2 represents an inverse tangent generator, and 22_3 represents an adder and subtractor;

[0061] 3 represents an error processing module;

[0062] 31 represents an amplifier, 32 represents a multiplier and divider, and 33 represents an integrator;

[0063] 4 represents the controller module;

[0064] 41 represents an amplitude controller, and 42 represents a phase controller. DETAILED DESCRIPTION

[0065] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0066] In the present invention, the terms "first", "second", etc. (if any) in the present invention and the accompanying drawings are used to distinguish similar objects but not necessarily to describe a specific order or sequence.

[0067] In order to solve the technical problems of long phase offset and delay of single-phase phase-locked loop phase-locked in actual power system, the present invention provides a single-phase phase-locked loop and amplitude-frequency two-dimensional tracking and control method based on the frequency doubling principle, and the overall idea is to increase the difference between harmonics and fundamental frequency in the process of tracking and controlling the original signal, so as to filter out the harmonics in the signal and improve the detection accuracy, while shortening the phase-locked period and increasing the phase-locked speed.

[0068] Based on the above inventive concept, in one embodiment of the present invention, a single-phase phase-locked loop based on the multi-frequency principle is provided, such as Figure 1 As shown, it includes: a multiple frequency processing module 1, an error calculation module 2 and a tracking control module;

[0069] The multi-frequency processing module 1 has a first input terminal for receiving a single-phase original signal U o (t) = A(t)cosθ(t), and its second input terminal is used to receive the measured amplitude A output by the tracking control moduleM (t), which is used to perform multiple frequency multiplication processing on the original signal and output phase information as the control signal X(t);

[0070] The error calculation module 2 has a first input end connected to the output end of the multi-frequency processing module 1, and a second input end connected to the output end of the tracking control module, which is used to calculate the amplitude error and phase error of the control phasor relative to the tracking signal to obtain the amplitude error control signal ΔA y (t) and the phase error control signal Δθ y (t); the projections of the control phasor on the α and β axes are A M (t)sinθ M (t) and A M (t)X(t), the amplitude and phase of the tracking signal are the measured amplitude A output by the tracking control module M (t) and the measured phase θ M (t);

[0071] The tracking control module has an input end connected to the output end of the error calculation module 2, which is used to filter out the amplitude error control signal ΔA y (t) and the phase error control signal Δθ y The high-frequency components in (t) are obtained, and the amplitude error ΔA(t) and phase error Δθ(t) of the original signal after multiple frequency processing relative to the tracking signal are obtained. The control target is to make the error zero. Combined with the given initial amplitude value and initial phase value, new measured amplitude and measured phase are obtained to achieve real-time tracking of amplitude and phase.

[0072] In this embodiment, by first multiplying the original signal and then performing phase locking, the difference between the harmonics and the fundamental frequency in the original signal is increased, so that the high-frequency component can be accurately removed to obtain a signal in a specific frequency band. At the same time, based on the relationship between the period T and the frequency ω, that is, Since the frequency increases after frequency doubling, the frequency locking period will be shortened accordingly. Therefore, this embodiment can also shorten the phase locking delay time by performing multiple frequency doubling processing on the original signal, thereby achieving an accurate and fast phase locking function.

[0073] Based on the principle of multiple frequency multiplication, in this embodiment, the calculation expression of the control signal obtained by the multiple frequency multiplication processing module 1 performing multiple frequency multiplication processing on the original signal is:

[0074]

[0075] Where n represents the frequency doubling times, and n>1; cosθ in the above formula (1) X (t), the original signal A(t)cosθ(t) and the measured amplitude A M(t) is taken as the quotient to obtain the approximate per unit value, namely:

[0076]

[0077] According to the above formula (2), if the amplitude of the signal is fully tracked, then cosθ X (t) is the cosine value of the original signal phase; if the amplitude of the signal is not completely tracked, but after the frequency multiplication and subsequent processing of the controller module, the error caused by the failure to track can be filtered or eliminated, so it can still be approximately expressed as the cosine value of the original signal phase. Therefore, in this embodiment, when the original signal is subjected to multiple frequency multiplication processing, according to Calculate cosθ X (t);

[0078] In practical applications, the frequency multiplication number n can be set accordingly according to actual application requirements. The larger the frequency multiplication number n is set, the smaller the corresponding phase-locked time delay is, but it also means that the sensitivity of the phase-locked loop to disturbances is greater. If it is set too large, it will cause the power electronic equipment to perform unnecessary operations under disturbances. As an optional implementation method, in order to ensure that the phase-locked loop is not too sensitive to power grid disturbances while shortening the phase-locked time delay, in this embodiment, n=4. At this time, the calculation expression of the control signal obtained by the multi-frequency processing module 1 performing multi-frequency processing on the original signal is:

[0079]

[0080] Accordingly, in this embodiment, the structure of the multi-frequency processing module 1 is as follows: Figure 2 As shown, it includes: a multiplier and divider 11, a power device 12, an amplifier 13 and an adder and subtractor 14; it should be noted that the number of times of multiplication processing and the specific structure of the corresponding multiplication processing module are only optional implementations and should not be understood as the only limitation of the present invention;

[0081] Based on the above formula (3), the multi-frequency processing module 1 will output the control signal X(t) after the quadruple frequency processing as the control object of the subsequent error calculation module 2.

[0082] The AC signal can be represented by a rotating phasor, and the length and rotation speed of the phasor correspond to the actual AC signal amplitude and frequency. However, since what can be directly measured is the instantaneous value of the original signal, it is impossible to directly obtain the amplitude, frequency and phase information of the AC signal at every moment, which means that it is impossible to directly obtain the phasor corresponding to the original signal. In order to make the measured tracking signal able to completely track the original signal and achieve a complete phase-locked function, this embodiment will further combine the measured amplitude A after obtaining the control signal X(t) by multi-frequency processing. M (t) and the measured phase θM (t) Construct the control phasor, such as Figure 3 As shown, the projections of the control phasor on the α and β axes are A M (t)sinθ M (t) and A M (txt), Figure 3 In the embodiment, the measured phasor and the actual phasor represent the phasors corresponding to the tracking signal and the original signal respectively; in this embodiment, the error between the control phasor and the tracking signal is controlled, that is, the amplitude error control signal ΔA is controlled. y (t) and the phase error control signal Δθ y (t) Control is performed. When the control phasor completely tracks the measured phasor, the three phasors shown in the figure: the control phasor, the measured phasor and the actual phasor are completely overlapped, thus achieving a complete phase-locking function.

[0083] based on Figure 3 It can be seen from the phasor relationship shown in the figure that in this embodiment, the constructed control phasor is relative to the error between the tracking signals, that is, the amplitude error control signal ΔA y (t) and the phase error control signal Δθ y (t), the calculation expressions are:

[0084]

[0085] Accordingly, if Figure 1 As shown, in this embodiment, the error calculation module 2 includes: an amplitude error calculation module 21 and a phase error calculation module 22, the input ends of the two together constitute the input end of the error calculation module 2, and the output ends together constitute the output end of the error calculation module 2;

[0086] Amplitude error calculation module 21, used according to Calculate the amplitude error of the control phasor relative to the tracking signal to obtain the amplitude error control signal ΔA y (t); The specific structure of the amplitude error calculation module 21 is as follows Figure 4 As shown, it includes a sine generator 21_1, a multiplier 21_2, a squarer 21_3, an adder 21_4, a square rooter 21_5 and an adder-subtractor 21_6;

[0087] The phase error calculation module 22 is used to calculate the phase error according to Calculate the phase error of the control phasor relative to the tracking signal and obtain the phase error control signal Δθ y (t); The specific structure of the phase error calculation module 22 is as follows Figure 5 As shown, it includes a sine generator 22_1, an inverse tangent generator 22_2 and an adder-subtractor 22_3.

[0088] In this embodiment, by Figure 3 It can be seen that the control phasor, the measured phasor and the actual phasor are geometrically related. The amplitude error control signal ΔA output by the error calculation module 2 is y (t) and the phase error control signal Δθ y (t) contains the error of the tracking signal relative to the original signal after multiplication. y (t) and Δθ y The high frequency component in (t) can be extracted to obtain the error of the tracking signal relative to the original signal after multiple frequency processing, that is, the amplitude error ΔA(t) and the phase error Δθ(t). As an optional implementation, Figure 1 As shown, in this embodiment, the error processing module 3 includes an amplitude error processing module and a phase error processing module, the input ends of the two together constitute the input end of the error processing module 3, and the output ends of the two together constitute the output end of the error processing module 3;

[0089] Amplitude error processing module, used to filter out the amplitude error control signal ΔA y The high-frequency component in (t) is obtained, and the amplitude error ΔA(t) of the original signal after multiple frequency processing relative to the tracking signal is obtained;

[0090] Phase error processing module, used to filter out the phase error control signal Δθ y The high-frequency component in (t) is obtained, and the phase error Δθ(t) of the original signal after multiple frequency processing relative to the tracking signal is obtained;

[0091] In practical applications, the amplitude error processing module and the phase error processing module can be implemented in a variety of ways. As an optional implementation, in this embodiment, the amplitude error processing module and the phase error processing module are implemented in a plurality of ways. M The high-frequency components in the amplitude / phase error control signal are filtered out by averaging the signal within a specific time length of the cycle (t), and the amplitude error ΔA(t) and phase error Δθ(t) are obtained. The corresponding calculation formulas are:

[0092]

[0093]

[0094] Accordingly, the structure of the amplitude / phase error processing module is as follows: Figure 6 As shown, it includes an amplifier 31, a multiplier and divider 32 and an integrator 33;

[0095] Among them, ω M (t) represents the measured frequency of the original signal after multi-frequency processing, which is related to the measured phase θ M The relationship between (t) is as follows:

[0096]

[0097] In this embodiment, the amplitude error control signal ΔA y (t) / phase error control signal Δθ y (t) The average value is calculated by taking the period of twice the measurement frequency. After the n-fold frequency processing, the error is integrated with 2n times the frequency time, which can remove the high-frequency component and better realize amplitude / phase tracking.

[0098] It should be noted that Figure 6 The structure shown is only an optional implementation of the present invention and should not be understood as the only limitation of the present invention. For example, in some other embodiments of the present invention, the integration processing period can also be set to other time lengths other than the 2-time frequency measurement frequency period, with T and T M Represent the integral processing period and the measurement frequency period respectively, then the setting of T satisfies (m is a positive integer). In some other embodiments of the present invention, other schemes may be used to implement the amplitude error processing module and the phase error processing module. For example, in some optional embodiments of the present invention, Figure 7 As shown, a low-pass filter can be directly used to implement the amplitude error processing module and the phase error processing module. More implementation methods will not be listed here one by one.

[0099] After the amplitude error ΔA(t) and phase error Δθ(t) of the tracking signal relative to the original signal are calculated, in order to enable the single-phase phase-locked loop to quickly track the original signal, the amplitude error ΔA(t) and phase error Δθ(t) should be close to zero. Therefore, in this embodiment,

[0100] The control target is to make the error zero. When the controller module 4 performs control, its control target is to make the error zero. To achieve this target, the control method of the amplitude / phase controller module can be implemented in a variety of ways, such as PI controller, using a delay module, etc. Optionally, in this embodiment, Figure 1 As shown, the controller module 4 includes: an amplitude controller 41 and a phase controller 42, the input ends of the two together constitute the input end of the controller module 4, and the output ends of the two together constitute the output end of the controller module 4;

[0101] The amplitude controller 41 is used to perform PI control on the amplitude error ΔA(t) and obtain a new measurement amplitude in combination with a given initial amplitude value. The specific structure of the amplitude controller 41 is as follows: Figure 8As shown, it includes a PI controller and an adder. For the input amplitude error ΔA(t), it first passes through the PI controller, sets the P parameter to achieve fast tracking of the controller, sets the I parameter to achieve zero static error tracking of the controller, and finally realizes instant tracking of the amplitude in combination with the initial value of the amplitude, and outputs the measured amplitude.

[0102] The phase controller 42 is used to perform PI control on the phase error Δθ(t), and then obtain a new measurement frequency in combination with a given frequency initial value, and then obtain a new measurement phase in combination with a given phase initial value after integrating the new measurement frequency. The specific structure of the phase controller 42 is as follows: Fig. 9 As shown, it includes a PI controller, an adder and an integral link. For the input phase error Δθ(t), it first passes through the PI controller. As above, the P parameter is set to achieve fast tracking of the controller, and the I parameter is set to achieve zero static error tracking of the controller. Combined with the initial value of the frequency, the measured frequency ω is obtained. M (t), then through the integration link, combined with the initial phase value, the phase is tracked instantly and the measured phase is output;

[0103] It is also important to note that Figure 8 and Fig. 9 The structure shown is only an optional embodiment of the present invention and should not be understood as the sole limitation of the present invention.

[0104] In general, this embodiment utilizes the multiple frequency processing module to perform multiple frequency processing on the single-phase original signal, and utilizes the subsequent error calculation module, error processing module and controller module to calculate and control the error, thereby realizing a fast and accurate phase locking function.

[0105] Based on the inventive concept proposed by the present invention, in another embodiment of the present invention, a single-phase phase-locked loop based on the multi-frequency principle is provided. This embodiment is similar to the above embodiment, and also includes a multi-frequency processing module 1, an error calculation module 2 and a tracking control module, and the functions of each module are the same, except that, in this embodiment, the tracking control module includes: an amplitude pre-compensation module, an amplitude tracking module, a phase error processing module and a phase controller; the input ends of the amplitude pre-compensation module and the phase error processing module together constitute the input end of the tracking control module, the input end of the amplitude tracking module is connected to the output end of the amplitude pre-compensation module, the input end of the phase controller is connected to the output end of the phase error processing module, and the output end of the amplitude tracking module and the output end of the phase processor together constitute the output end of the tracking control module;

[0106] Amplitude pre-compensation module (not shown in the figure) uses amplitude error control signal ΔA y (t) for the measured amplitude A M (t) is compensated to obtain the signal S′=ΔA y(t)+A M (t);

[0107] Amplitude tracking modules, such as Fig.10 As shown, it is used to filter out the high-order harmonics in the signal S′ to obtain a new measurement amplitude; the amplitude tracking module can be implemented in a variety of ways, such as a low-pass filter, a delay module, etc.;

[0108] Phase error processing module, used to filter out the phase error control signal Δθ y The high-frequency component in (t) is obtained, and the phase error Δθ(t) of the original signal after multiple frequency processing relative to the tracking signal is obtained;

[0109] A phase controller is used to perform PI control on the phase error Δθ(t), and then obtain a new measurement frequency in combination with a given frequency initial value, and then obtain a new measurement phase in combination with a given phase initial value after integrating the new measurement frequency;

[0110] The specific implementation of the phase error processing module and the phase controller in this embodiment can refer to the description in the previous embodiment, and will not be repeated here.

[0111] In another embodiment of the present invention, a two-dimensional amplitude-frequency tracking control method based on the multi-frequency principle is provided. Fig.11 As shown, including:

[0112] The received single-phase original signal U o (t) = A(t)cosθ(t) after multiple frequency processing, the output phase information is used as the control signal X(t);

[0113] Calculate the amplitude error and phase error of the control phasor relative to the tracking signal to obtain the amplitude error control signal ΔA y (t) and the phase error control signal Δθ y (t); the projections of the control phasor on the α and β axes are A M (t)sinθ M (t) and A M (t)X(t), the amplitude and phase of the tracking signal are respectively the measured amplitude A of the feedback input M (t) and the measured phase θ M (t);

[0114] Filter the amplitude error control signal ΔA y (t) and the phase error control signal Δθ yThe high-frequency components in (t) are obtained, and the amplitude error ΔA(t) and phase error Δθ(t) of the original signal after multiple frequency processing relative to the tracking signal are obtained, and the control is performed with the error being zero as the control target. Combined with the given initial amplitude value and initial phase value, new measurement amplitude and measurement phase are obtained to achieve real-time tracking of amplitude and phase;

[0115] In this embodiment, the specific implementation of each step can refer to the description in the above embodiment of the single-phase phase-locked loop, which will not be repeated here.

[0116] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A single-phase phase-locked loop based on the principle of multiple frequency multiplication, characterized in that: include: A multiple frequency processing module (1), an error calculation module (2) and a tracking control module; The multi-frequency processing module (1) has a first input end for receiving a single-phase original signal U o (t) = A(t)cosθ(t), and its second input terminal is used to receive the measured amplitude A output by the tracking control module M (t), which is used to perform multiple frequency multiplication processing on the original signal and output phase information as a control signal X(t); The error calculation module (2), whose first input end is connected to the output end of the multi-frequency processing module (1), and whose second input end is connected to the output end of the tracking control module, is used to calculate the amplitude error and phase error of the control phasor relative to the tracking signal to obtain the amplitude error control signal ΔA y (t) and the phase error control signal Δθ y (t); the projections of the control phasor on the α and β axes are A M (t)sinθ M (t) and A M (t)X(t), the amplitude and phase of the tracking signal are the measured amplitude A output by the tracking control module M (t) and the measured phase θ M (t); The tracking control module, whose input end is connected to the output end of the error calculation module (2), is used to filter out the amplitude error control signal ΔA. y (t) and the phase error control signal Δθ y The high-frequency component in (t) is obtained, and the amplitude error ΔA(t) and phase error Δθ(t) of the original signal after multiple frequency processing relative to the tracking signal are obtained, and the error is controlled to be zero as the control target. Combined with the given initial amplitude value and initial phase / frequency value, new measured amplitude and measured phase / frequency are obtained to realize real-time tracking of amplitude and phase / frequency.

2. The single-phase phase-locked loop based on the multi-frequency principle as claimed in claim 1, characterized in that: The error calculation module (2) comprises: an amplitude error calculation module (21) and a phase error calculation module (22), the input ends of the two together constitute the input end of the error calculation module (2), and the output ends of the two together constitute the output end of the error calculation module (2); The amplitude error calculation module (21) is used to calculate the amplitude error according to Calculate the amplitude error of the control phasor relative to the tracking signal to obtain the amplitude error control signal ΔA y (t); The phase error calculation module (22) is used to calculate the phase error according to Calculate the phase error of the control phasor relative to the tracking signal and obtain the phase error control signal Δθ y (t).

3. The single-phase phase-locked loop based on the multi-frequency principle as claimed in claim 1, characterized in that: The tracking control module comprises: an error processing module (3) and a controller module (4); The error processing module (3), whose input end is used as the input end of the tracking control module, is used to filter out the amplitude error control signal ΔA y (t) and the phase error control signal Δθ y (t), and obtain the amplitude error ΔA(t) and phase error Δθ(t) of the original signal after multiple frequency processing relative to the tracking signal; The controller module (4) has an input end connected to the output end of the error processing module (3), and an output end serving as the output end of the tracking control module, and is used to control the error to zero as a control target, and to obtain a new measured amplitude and measured phase / frequency in combination with a given initial amplitude value and an initial phase / frequency value.

4. The single-phase phase-locked loop based on the multi-frequency principle as claimed in claim 3, characterized in that: The error processing module (3) comprises: an amplitude error processing module and a phase error processing module, the input ends of the two modules together constitute the input end of the error processing module (3), and the output ends of the two modules together constitute the output end of the error processing module (3); The amplitude error processing module is used to filter out the amplitude error control signal ΔA y (t), and obtain the amplitude error ΔA(t) of the original signal after multiple frequency processing relative to the tracking signal; The phase error processing module is used to filter out the phase error control signal Δθ y The high-frequency component in (t) is obtained to obtain the phase error Δθ(t) of the original signal after multiple frequency processing relative to the tracking signal.

5. The single-phase phase-locked loop based on the multi-frequency principle as claimed in claim 4, characterized in that: The amplitude error processing module is a low-pass filter, or the amplitude error processing module is based on Calculate the amplitude error ΔA(t); Wherein, m is a positive integer.

6. The single-phase phase-locked loop based on the multi-frequency principle as claimed in claim 4, characterized in that: The phase error processing module is a low-pass filter, or the phase error processing module is Calculate the phase error Δθ(t); Wherein, m is a positive integer.

7. The single-phase phase-locked loop based on the multi-frequency principle as claimed in any one of claims 3 to 6, characterized in that: The controller module (4) comprises: an amplitude controller (41) and a phase controller (42), the input ends of the two controllers together constitute the input end of the controller module (4), and the output ends of the two controllers together constitute the output end of the controller module (4); The amplitude controller (41) is used to obtain a new measurement amplitude after performing PI control on the amplitude error ΔA(t) in combination with a given initial amplitude value; The phase controller (42) is used to perform PI control on the phase error Δθ(t), and then obtain a new measurement frequency in combination with a given frequency initial value, and to integrate the new measurement frequency and then obtain a new measurement phase in combination with a given phase initial value.

8. The single-phase phase-locked loop based on the multi-frequency principle as claimed in claim 1, characterized in that: The tracking control module comprises: an amplitude pre-compensation module, an amplitude tracking module, a phase error processing module and a phase controller; the input ends of the amplitude pre-compensation module and the phase error processing module together constitute the input end of the tracking control module, the input end of the amplitude tracking module is connected to the output end of the amplitude pre-compensation module, the input end of the phase controller is connected to the output end of the phase error processing module, and the output end of the amplitude tracking module and the output end of the phase controller together constitute the output end of the tracking control module; The amplitude pre-compensation module uses the amplitude error control signal ΔA y (t) for the measured amplitude A M (t) is compensated to obtain the signal S′=ΔA y (t)+A M (t); The amplitude tracking module is used to filter out the higher harmonics in the signal S′ to obtain a new measurement amplitude; The phase error processing module is used to filter out the phase error control signal Δθ y (t), and obtain the phase error Δθ(t) of the original signal after multiple frequency processing relative to the tracking signal; The phase controller is used to perform PI control on the phase error Δθ(t), and then obtain a new measurement frequency in combination with a given frequency initial value, and to integrate the new measurement frequency in combination with a given phase initial value to obtain a new measurement phase.

9. The single-phase phase-locked loop based on the multi-frequency principle as claimed in any one of claims 1 to 6 and 8, characterized in that: The calculation expression of the control signal obtained by the multiple frequency processing module (1) performing multiple frequency processing on the original signal is: in, n represents the frequency doubling times, and n>

1.

10. A two-dimensional amplitude-frequency tracking control method based on the principle of multiple frequency doubling, characterized in that: include: The received single-phase original signal U o (t) = A(t)cosθ(t) after multiple frequency processing, the output phase information is used as the control signal X(t); Calculate the amplitude error and phase error of the control phasor relative to the tracking signal to obtain the amplitude error control signal ΔA y (t) and the phase error control signal Δθ y (t); the projections of the control phasor on the α and β axes are A M (t)sinθ M (t) and A M (t)X(t), the amplitude and phase of the tracking signal are respectively the measured amplitude A of the feedback input M (t) and the measured phase θ M (t); Filter out the amplitude error control signal ΔA y (t) and the phase error control signal Δθ y The high-frequency component in (t) is obtained, and the amplitude error ΔA(t) and phase error Δθ(t) of the original signal after multiple frequency processing relative to the tracking signal are obtained, and the error is controlled to be zero as the control target. Combined with the given initial amplitude value and initial phase value, new measured amplitude and measured phase are obtained to realize real-time tracking of amplitude and phase.

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