CN111044784A - Method and device for obtaining load impedance angle - Google Patents
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Abstract
本申请实施例公开了一种负载阻抗角获取方法及装置，该方法中，对所获取的负载电压以及负载电流同时进行滤波，获取滤波信号，并根据所述滤波信号，获取初始脉冲信号以及初始脉冲信号的脉冲峰值，接着根据所述脉冲峰值，获取第一积分值以及第二积分值，进而获取所述负载电压与所述负载电流之间的相位差绝对值。然后通过获取负载阻抗性质，获取负载阻抗角系数，根据所述相位差绝对值以及所述负载阻抗角系数，获取负载阻抗角的大小。上述方法通过对负载电压和负载电流同时进行滤波，消除了延迟所产生的误差，并结合负载阻抗性质，通过计算得到负载阻抗角，保证结果的精确度。
The embodiment of the present application discloses a method and device for obtaining a load impedance angle. In the method, the obtained load voltage and load current are simultaneously filtered to obtain a filtered signal, and according to the filtered signal, an initial pulse signal and an initial pulse signal are obtained. The pulse peak value of the pulse signal, and then obtain the first integral value and the second integral value according to the pulse peak value, and then obtain the absolute value of the phase difference between the load voltage and the load current. Then, the load impedance angle coefficient is obtained by obtaining the load impedance property, and the magnitude of the load impedance angle is obtained according to the absolute value of the phase difference and the load impedance angle coefficient. The above method eliminates the error caused by the delay by filtering the load voltage and the load current at the same time, and combines the load impedance property to obtain the load impedance angle through calculation to ensure the accuracy of the result.
Description
Technical Field
The present application relates to the field of power systems, and in particular, to a method and an apparatus for obtaining a load impedance angle.
Background
The load impedance angle refers to a phase difference between a current and a voltage of the load impedance when the load impedance is introduced with alternating current. In order to improve the utilization efficiency of various grid-connected inverters and industrial production rectification power supplies in a power system, a load impedance angle needs to be detected, and the phase difference between current and voltage needs to be acquired so as to carry out accurate compensation.
At present, when a load impedance angle is detected, the initial phases of load voltage and current are generally obtained through a phase discriminator, and then the frequency of grid voltage is tracked through a PI control method, so that the load impedance angle is obtained. When the frequency of the power grid voltage is tracked by the PI control method, the fundamental component of the power grid voltage needs to be tracked. When the terminal voltage of the power distribution network has a large distortion rate, because the power grid voltage has more harmonic components, under the condition, before the frequency of the power grid voltage is tracked by using a PI control method, the harmonic components in the power grid voltage need to be filtered by using a filter, but the harmonic components in the power grid voltage are filtered by using the filter, so that the voltage is delayed, the voltage phase is delayed, and finally the acquired load impedance angle has an error.
Disclosure of Invention
In order to solve the problem that a filter is needed to filter harmonic components in the power grid voltage before a PI control method is used for tracking the frequency of the power grid voltage, so that an error occurs in a finally obtained load impedance angle, the application discloses a method and a device for obtaining the load impedance angle through the following embodiments.
The first aspect of the present application discloses a method for obtaining a load impedance angle, the method comprising:
acquiring load voltage and load current;
filtering the load voltage and the load current simultaneously to obtain filtering signals, wherein the filtering signals comprise load voltage filtering signals and load current filtering signals;
acquiring an initial pulse signal according to the filtering signal, wherein the initial pulse signal comprises a voltage initial pulse signal and a current initial pulse signal;
acquiring a pulse peak value of the initial pulse signal according to the initial pulse signal;
acquiring a first integral value according to the pulse peak value, wherein the first integral value is a result of integrating the voltage initial pulse signal;
acquiring a second integral value according to the pulse peak value, wherein the second integral value is a result of integrating a combined pulse signal, the combined pulse signal is a pulse signal formed by combining the voltage initial pulse signal and a current initial pulse opposite signal, and the current initial pulse opposite signal is a pulse signal obtained by inverting the current initial pulse signal;
acquiring an absolute value of a phase difference between the load voltage and the load current according to the first integrated value and the second integrated value;
acquiring load impedance properties, and acquiring load impedance angle coefficients according to the load impedance properties;
and acquiring the magnitude of the load impedance angle according to the absolute value of the phase difference and the load impedance angle coefficient.
Optionally, the obtaining a first integrated value according to the pulse peak value includes:
the first integrated value is obtained by the following formula:
wherein S represents the first integrated value, uLCRepresenting the voltage initial pulse signal and M representing the pulse peak.
Optionally, the obtaining a second integrated value according to the pulse peak value includes:
acquiring the second integrated value by the following formula:
wherein Δ S represents the second integrated value,
representing the current initial pulse opposite signal, α representing a reference variable whose magnitude coincides with the magnitude of the absolute value of the phase difference.
Optionally, the obtaining an absolute value of a phase difference between the load voltage and the load current according to the first integrated value and the second integrated value includes:
obtaining the absolute value of the phase difference according to the following formula:
where | θ | represents the absolute value of the phase difference.
Optionally, the load impedance angle coefficient is 1, -1 or 0.
Optionally, the obtaining of the load impedance property and obtaining the load impedance angle coefficient according to the load impedance property includes:
when the load voltage passes through zero, acquiring the magnitude of an instantaneous value of the load current;
acquiring the load impedance property according to the instantaneous value of the load current, wherein the load impedance property is an inductive load, a capacitive load or a pure resistance load;
if the load impedance property is an inductive load, acquiring that the load impedance angular coefficient is 1; or if the load impedance property is a capacitive load, obtaining that the load impedance angle coefficient is-1; or, if the load impedance property is a pure resistive load, obtaining that the load impedance angular coefficient is 0.
Optionally, the obtaining the load impedance property according to the magnitude of the instantaneous value of the load current includes:
if the instantaneous value of the load current is less than 0, acquiring the load impedance property as an inductive load;
or, if the instantaneous value of the load current is greater than 0, acquiring the load impedance property as a capacitive load;
or, if the instantaneous value of the load current is equal to 0, the load impedance property is acquired as a pure resistive load.
A second aspect of the present application discloses a load impedance angle acquisition apparatus, which is applied to a load impedance angle acquisition method disclosed in the first aspect of the present application, and the apparatus includes:
the voltage and current acquisition module is used for acquiring load voltage and load current;
the filtering module is used for simultaneously filtering the load voltage and the load current to obtain filtering signals, and the filtering signals comprise load voltage filtering signals and load current filtering signals;
the initial pulse signal acquisition module is used for acquiring an initial pulse signal according to the filtering signal, wherein the initial pulse signal comprises a voltage initial pulse signal and a current initial pulse signal;
the pulse peak value acquisition module is used for acquiring a pulse peak value of the initial pulse signal according to the initial pulse signal;
the first integration module is used for acquiring a first integration value according to the pulse peak value, wherein the first integration value is a result of integrating the voltage initial pulse signal;
the second integration module is used for acquiring a second integration value according to the pulse peak value, wherein the second integration value is a result of integrating a combined pulse signal, the combined pulse signal is a pulse signal formed by combining the voltage initial pulse signal and a current initial pulse opposite signal, and the current initial pulse opposite signal is a pulse signal obtained by inverting the current initial pulse signal;
a phase difference absolute value acquisition module, configured to acquire a phase difference absolute value between the load voltage and the load current according to the first integrated value and the second integrated value;
the load impedance angle coefficient acquisition module is used for acquiring load impedance properties and acquiring load impedance angle coefficients according to the load impedance properties;
and the load impedance angle acquisition module is used for acquiring the magnitude of the load impedance angle according to the absolute value of the phase difference and the load impedance angle coefficient.
Optionally, the first integration module includes:
a first integration unit configured to acquire the first integrated value according to the following formula:
wherein S represents the first integrated value, uLCRepresenting the voltage initial pulse signal and M representing the pulse peak.
Optionally, the second integration module includes:
a second integration unit configured to acquire the second integrated value by the following equation:
wherein Δ S represents the second integrated value,
representing the current initial pulse opposite signal, α representing a reference variable whose magnitude coincides with the magnitude of the absolute value of the phase difference.
Optionally, the phase difference absolute value obtaining module includes:
a phase difference absolute value calculating unit, configured to obtain the phase difference absolute value according to the following formula:
where | θ | represents the absolute value of the phase difference.
Optionally, the load impedance angle coefficient obtaining module includes:
the current instantaneous value acquisition unit is used for acquiring the magnitude of the instantaneous value of the load current when the load voltage passes through zero;
the impedance property acquisition unit is used for acquiring the load impedance property according to the instantaneous value of the load current, wherein the load impedance property is an inductive load, a capacitive load or a pure resistance load;
a coefficient obtaining unit, configured to obtain that the load impedance angular coefficient is 1 when the load impedance property is an inductive load; or, when the load impedance property is a capacitive load, obtaining that the load impedance angle coefficient is-1; or, when the load impedance property is a pure resistive load, obtaining that the load impedance angular coefficient is 0.
Optionally, the impedance property obtaining unit includes:
the inductive judging subunit is used for acquiring the load impedance property as an inductive load when the instantaneous value of the load current is less than 0;
the capacitive judging subunit is used for acquiring the load impedance property as a capacitive load when the instantaneous value of the load current is greater than 0;
and the pure resistance judging subunit is used for acquiring that the load impedance property is a pure resistance load when the instantaneous value of the load current is equal to 0.
The embodiment of the application discloses a method and a device for acquiring a load impedance angle. And then obtaining a load impedance angle coefficient by obtaining the load impedance property, and obtaining the magnitude of a load impedance angle according to the phase difference absolute value and the load impedance angle coefficient. According to the method, the load voltage and the load current are filtered simultaneously, errors caused by delay are eliminated, the load impedance angle is obtained through calculation by combining the load impedance property, and the accuracy of the result is guaranteed.
Drawings
In order to more clearly explain the technical solution of the present application, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious to those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.
Fig. 1 is a schematic workflow diagram of a load impedance angle obtaining method disclosed in an embodiment of the present application;
fig. 2 is a schematic circuit diagram illustrating a load impedance angle obtaining method according to an embodiment of the present disclosure;
fig. 3 is a schematic structural diagram of a load impedance angle obtaining apparatus according to an embodiment of the present application.
Detailed Description
In order to solve the problem that a filter is needed to filter harmonic components in the power grid voltage before a PI control method is used for tracking the frequency of the power grid voltage, so that an error occurs in a finally obtained load impedance angle, the application discloses a method and a device for obtaining the load impedance angle through the following embodiments.
The first embodiment of the present application discloses a method for obtaining a load impedance angle, which includes:
in step S11, a load voltage and a load current are obtained.
Step S12, filtering the load voltage and the load current simultaneously to obtain filtered signals, where the filtered signals include a load voltage filtered signal and a load current filtered signal.
In practical application, two identical low-pass filters are used for filtering the load voltage and the load current at the same time respectively, and harmonic components in the load voltage and the load current are filtered out. The delays generated by the same filter can be mutually offset in the calculation process, so that the accuracy of the calculated load impedance angle is ensured.
Step S13, obtaining an initial pulse signal according to the filtered signal, where the initial pulse signal includes a voltage initial pulse signal and a current initial pulse signal.
The voltage phase discriminator is used for processing the load voltage filtering signal to obtain a voltage initial pulse signal, and the current phase discriminator is used for processing the load current filtering signal to obtain a current initial pulse signal.
Fig. 2 is a schematic circuit diagram illustrating a load impedance angle obtaining method according to an embodiment of the present application, in which a load voltage u is shownLAfter passing through a Low Pass Filter (LPF), a voltage initial pulse signal u is obtained by processing of a voltage phase discriminatorLCLoad current iLAfter passing through a Low Pass Filter (LPF), a current initial pulse signal i is obtained by processing of a current phase discriminatorLC。
And step S14, acquiring a pulse peak value of the initial pulse signal according to the initial pulse signal. The pulse peak value of the voltage initial pulse signal is consistent with the pulse peak value of the current initial pulse signal in size.
In step S15, a first integrated value is obtained according to the pulse peak value, and the first integrated value is the result of integrating the voltage initial pulse signal.
In one implementation, the first integrated value is obtained by the following equation:
wherein S represents the first integrated value, uLCRepresenting the voltage initial pulse signal and M representing the pulse peak.
Step S16, obtaining a second integral value according to the pulse peak value, where the second integral value is a result of integrating a merged pulse signal, the merged pulse signal is a pulse signal obtained by merging the voltage initial pulse signal and a current initial pulse opposite signal, and the current initial pulse opposite signal is a pulse signal obtained by inverting the current initial pulse signal.
In one implementation, the second integrated value is obtained by the following equation:
wherein Δ S represents the second integrated value,
representing the current initial pulse reversal signal, α representing the reference variable, α corresponding to an intermediate transformed variable, the magnitude of which corresponds to the magnitude of the absolute value of the phase difference.
Step S17 is to obtain an absolute value of a phase difference between the load voltage and the load current based on the first integrated value and the second integrated value.
In one implementation, dividing the first integrated value by the second integrated value can result in:
obtaining the absolute value of the phase difference by conversion according to the following formula:
where | θ | represents the absolute value of the phase difference.
Step S18, obtaining a load impedance property, and obtaining a load impedance angle coefficient according to the load impedance property.
And step S19, obtaining the magnitude of the load impedance angle according to the absolute value of the phase difference and the load impedance angle coefficient.
In the embodiment of the present application, the absolute value of the phase difference is multiplied by the load impedance angle coefficient to obtain a load impedance angle, and a calculation formula is as follows: and theta is k-pi-delta S/S, wherein theta is the load impedance angle, and k is the load impedance angle coefficient.
The embodiment of the application discloses a method and a device for acquiring a load impedance angle. And then obtaining a load impedance angle coefficient by obtaining the load impedance property, and obtaining the magnitude of a load impedance angle according to the phase difference absolute value and the load impedance angle coefficient. According to the method, the load voltage and the load current are filtered simultaneously, errors caused by delay are eliminated, the load impedance angle is obtained through calculation by combining the load impedance property, and the accuracy of the result is guaranteed.
Further, the load impedance angle coefficient is 1, -1 or 0.
Further, the obtaining of the load impedance property and obtaining the load impedance angle coefficient according to the load impedance property includes:
and when the load voltage passes through zero, acquiring the instantaneous value of the load current.
And acquiring the load impedance property according to the instantaneous value of the load current, wherein the load impedance property is an inductive load, a capacitive load or a pure resistance load.
And if the load impedance property is an inductive load, acquiring that the load impedance angular coefficient is 1. Or, if the load impedance property is a capacitive load, obtaining that the load impedance angular coefficient is-1. Or, if the load impedance property is a pure resistive load, obtaining that the load impedance angular coefficient is 0.
Further, the obtaining the load impedance property according to the magnitude of the instantaneous value of the load current includes:
and if the instantaneous value of the load current is less than 0, acquiring the load impedance property as an inductive load.
Or, if the instantaneous value of the load current is greater than 0, acquiring the load impedance property as a capacitive load.
Or, if the instantaneous value of the load current is equal to 0, the load impedance property is acquired as a pure resistive load.
In fig. 2, the filtered load voltage signal and the filtered load current signal are compared by a comparator, and then the positive and negative signals output by the comparator are obtained through a sign function sgn, and the sampling holder SH collects the positive and negative signals and outputs a load impedance angle coefficient.
The second embodiment of the present application discloses a load impedance angle obtaining apparatus, which is applied to a load impedance angle obtaining method disclosed in the first embodiment of the present application, and the apparatus includes:
the voltage and current obtaining module 10 is configured to obtain a load voltage and a load current.
The filtering module 20 is configured to filter the load voltage and the load current simultaneously to obtain a filtering signal, where the filtering signal includes a load voltage filtering signal and a load current filtering signal.
An initial pulse signal obtaining module 30, configured to obtain an initial pulse signal according to the filtered signal, where the initial pulse signal includes a voltage initial pulse signal and a current initial pulse signal.
And a pulse peak value obtaining module 40, configured to obtain a pulse peak value of the initial pulse signal according to the initial pulse signal.
And a first integration module 50, configured to obtain a first integrated value according to the pulse peak value, where the first integrated value is a result of integrating the voltage initial pulse signal.
A second integration module 60, configured to obtain a second integrated value according to the pulse peak value, where the second integrated value is a result of integrating a merged pulse signal, the merged pulse signal is a pulse signal obtained by merging the voltage initial pulse signal and a current initial pulse opposite signal, and the current initial pulse opposite signal is a pulse signal obtained by inverting the current initial pulse signal.
A phase difference absolute value obtaining module 70, configured to obtain an absolute value of a phase difference between the load voltage and the load current according to the first integrated value and the second integrated value.
A load impedance angle coefficient obtaining module 80, configured to obtain load impedance properties, and obtain a load impedance angle coefficient according to the load impedance properties.
And a load impedance angle obtaining module 90, configured to obtain a magnitude of the load impedance angle according to the absolute value of the phase difference and the load impedance angle coefficient.
Further, the first integration module 50 includes:
a first integration unit configured to acquire the first integrated value according to the following formula:
wherein S represents the first integrated value, uLCRepresenting the voltage initial pulse signal and M representing the pulse peak.
Further, the second integration module 60 includes:
a second integration unit configured to acquire the second integrated value by the following equation:
wherein Δ S represents the second integrated value,
representing the current initial pulse opposite signal, α representing a reference variable whose magnitude coincides with the magnitude of the absolute value of the phase difference.
Further, the phase difference absolute value obtaining module 70 includes:
a phase difference absolute value calculating unit, configured to obtain the phase difference absolute value according to the following formula:
where | θ | represents the absolute value of the phase difference.
Further, the load impedance angle coefficient obtaining module 80 includes:
and the current instantaneous value acquisition unit is used for acquiring the magnitude of the instantaneous value of the load current when the load voltage passes through zero.
And the impedance property acquisition unit is used for acquiring the load impedance property according to the instantaneous value of the load current, wherein the load impedance property is an inductive load, a capacitive load or a pure resistance load.
And the coefficient acquisition unit is used for acquiring that the load impedance angular coefficient is 1 when the load impedance property is an inductive load. Or, when the load impedance property is a capacitive load, obtaining that the load impedance angle coefficient is-1. Or, when the load impedance property is a pure resistive load, obtaining that the load impedance angular coefficient is 0.
Further, the impedance property acquisition unit includes:
and the inductive judging subunit is used for acquiring the load impedance property as an inductive load when the instantaneous value of the load current is less than 0.
And the capacitive judging subunit is used for acquiring the load impedance property as a capacitive load when the instantaneous value of the load current is greater than 0.
And the pure resistance judging subunit is used for acquiring that the load impedance property is a pure resistance load when the instantaneous value of the load current is equal to 0.
The present application has been described in detail with reference to specific embodiments and illustrative examples, but the description is not intended to limit the application. Those skilled in the art will appreciate that various equivalent substitutions, modifications or improvements may be made to the presently disclosed embodiments and implementations thereof without departing from the spirit and scope of the present disclosure, and these fall within the scope of the present disclosure. The protection scope of this application is subject to the appended claims.
Claims (10)
1. A method for obtaining a load impedance angle, comprising:
acquiring load voltage and load current;
filtering the load voltage and the load current simultaneously to obtain filtering signals, wherein the filtering signals comprise load voltage filtering signals and load current filtering signals;
acquiring an initial pulse signal according to the filtering signal, wherein the initial pulse signal comprises a voltage initial pulse signal and a current initial pulse signal;
acquiring a pulse peak value of the initial pulse signal according to the initial pulse signal;
acquiring a first integral value according to the pulse peak value, wherein the first integral value is a result of integrating the voltage initial pulse signal;
acquiring a second integral value according to the pulse peak value, wherein the second integral value is a result of integrating a combined pulse signal, the combined pulse signal is a pulse signal formed by combining the voltage initial pulse signal and a current initial pulse opposite signal, and the current initial pulse opposite signal is a pulse signal obtained by inverting the current initial pulse signal;
acquiring an absolute value of a phase difference between the load voltage and the load current according to the first integrated value and the second integrated value;
acquiring load impedance properties, and acquiring load impedance angle coefficients according to the load impedance properties;
and acquiring the magnitude of the load impedance angle according to the absolute value of the phase difference and the load impedance angle coefficient.
2. The method of claim 1, wherein said obtaining a first integrated value based on said pulse peak value comprises:
the first integrated value is obtained by the following formula:
wherein S represents the first integrated value, uLCRepresenting said voltageAn initial pulse signal, M representing the peak of the pulse.
3. The method of claim 2, wherein said obtaining a second integrated value based on said pulse peak value comprises:
acquiring the second integrated value by the following formula:
wherein Δ S represents the second integrated value,
representing the current initial pulse opposite signal, α representing a reference variable whose magnitude coincides with the magnitude of the absolute value of the phase difference.
4. The method of claim 3, wherein the obtaining an absolute value of a phase difference between the load voltage and the load current from the first integrated value and the second integrated value comprises:
obtaining the absolute value of the phase difference according to the following formula:
where | θ | represents the absolute value of the phase difference.
5. The method of claim 1, wherein the load impedance angle factor is 1, -1, or 0.
6. The method of claim 5, wherein obtaining the load impedance property and obtaining the load impedance angle coefficient according to the load impedance property comprises:
when the load voltage passes through zero, acquiring the magnitude of an instantaneous value of the load current;
acquiring the load impedance property according to the instantaneous value of the load current, wherein the load impedance property is an inductive load, a capacitive load or a pure resistance load;
if the load impedance property is an inductive load, acquiring that the load impedance angular coefficient is 1; or if the load impedance property is a capacitive load, obtaining that the load impedance angle coefficient is-1; or, if the load impedance property is a pure resistive load, obtaining that the load impedance angular coefficient is 0.
7. The method of claim 6, wherein the obtaining the load impedance property according to the magnitude of the instantaneous value of the load current comprises:
if the instantaneous value of the load current is less than 0, acquiring the load impedance property as an inductive load;
or, if the instantaneous value of the load current is greater than 0, acquiring the load impedance property as a capacitive load;
or, if the instantaneous value of the load current is equal to 0, the load impedance property is acquired as a pure resistive load.
8. A load impedance angle acquisition apparatus, which is applied to a load impedance angle acquisition method according to any one of claims 1 to 7, the apparatus comprising:
the voltage and current acquisition module is used for acquiring load voltage and load current;
the filtering module is used for simultaneously filtering the load voltage and the load current to obtain filtering signals, and the filtering signals comprise load voltage filtering signals and load current filtering signals;
the initial pulse signal acquisition module is used for acquiring an initial pulse signal according to the filtering signal, wherein the initial pulse signal comprises a voltage initial pulse signal and a current initial pulse signal;
the pulse peak value acquisition module is used for acquiring a pulse peak value of the initial pulse signal according to the initial pulse signal;
the first integration module is used for acquiring a first integration value according to the pulse peak value, wherein the first integration value is a result of integrating the voltage initial pulse signal;
the second integration module is used for acquiring a second integration value according to the pulse peak value, wherein the second integration value is a result of integrating a combined pulse signal, the combined pulse signal is a pulse signal formed by combining the voltage initial pulse signal and a current initial pulse opposite signal, and the current initial pulse opposite signal is a pulse signal obtained by inverting the current initial pulse signal;
a phase difference absolute value acquisition module, configured to acquire a phase difference absolute value between the load voltage and the load current according to the first integrated value and the second integrated value;
the load impedance angle coefficient acquisition module is used for acquiring load impedance properties and acquiring load impedance angle coefficients according to the load impedance properties;
and the load impedance angle acquisition module is used for acquiring the magnitude of the load impedance angle according to the absolute value of the phase difference and the load impedance angle coefficient.
9. The apparatus of claim 8, wherein the first integration module comprises:
a first integration unit configured to acquire the first integrated value according to the following formula:
wherein S represents the first integrated value, uLCRepresenting the voltage initial pulse signal and M representing the pulse peak.
10. The apparatus of claim 9, wherein the second integration module comprises:
a second integration unit configured to acquire the second integrated value by the following equation:
wherein Δ S represents the second integrated value,
representing the current initial pulse opposite signal, α representing a reference variable whose magnitude coincides with the magnitude of the absolute value of the phase difference.
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| CN112526211A (en) * | 2020-12-31 | 2021-03-19 | 海南师范大学 | Method for dynamically measuring nonlinear load impedance |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57125856A (en) * | 1981-01-30 | 1982-08-05 | Toshiba Corp | Phase difference detecting device |
| US5463299A (en) * | 1989-06-07 | 1995-10-31 | Hitachi, Ltd. | Current controller for controlling a current flowing in a load using a PWM inverter and method used thereby |
| TW432777B (en) * | 1997-12-22 | 2001-05-01 | Abb Industry Oy | Method for defining instantaneous value of current of pulse-controlled inductive load |
| CN1488948A (en) * | 2003-08-08 | 2004-04-14 | 辉 耿 | Circuit load property and its voltage-current phase difference measuring method and apparatus |
| CN1783698A (en) * | 2001-09-29 | 2006-06-07 | 大金工业株式会社 | Phase current detection method, inverter control method, motor control method, and apparatuses used in these methods |
-
2020
- 2020-01-03 CN CN202010006096.8A patent/CN111044784A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57125856A (en) * | 1981-01-30 | 1982-08-05 | Toshiba Corp | Phase difference detecting device |
| US5463299A (en) * | 1989-06-07 | 1995-10-31 | Hitachi, Ltd. | Current controller for controlling a current flowing in a load using a PWM inverter and method used thereby |
| TW432777B (en) * | 1997-12-22 | 2001-05-01 | Abb Industry Oy | Method for defining instantaneous value of current of pulse-controlled inductive load |
| CN1783698A (en) * | 2001-09-29 | 2006-06-07 | 大金工业株式会社 | Phase current detection method, inverter control method, motor control method, and apparatuses used in these methods |
| CN1488948A (en) * | 2003-08-08 | 2004-04-14 | 辉 耿 | Circuit load property and its voltage-current phase difference measuring method and apparatus |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112526211A (en) * | 2020-12-31 | 2021-03-19 | 海南师范大学 | Method for dynamically measuring nonlinear load impedance |
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