Frequency regulation method and apparatus

Abstract

A frequency regulation method and apparatus is applied to an insulation impedance detection apparatus in a direct current power system, and relates to the field of security monitoring technologies of a direct current electrical system. The method includes: collecting sampling voltages at a sampling point for at least three time points; determining a voltage frequency regulation manner based on the sampling voltages, obtained through sampling, at the at least three time points; and then regulating a voltage frequency of a power supply according to the determined voltage frequency regulation manner. The voltage frequency of the power supply can be regulated based on the at least three sampling voltages obtained through sampling. Therefore, the insulation impedance detection apparatus reduces insulation impedance detection duration while ensuring accuracy of measured insulation impedance.

Claims

1. A frequency regulation method, applied to an insulation impedance detection apparatus in a direct current power system, comprising: collecting sampling voltages at a sampling point for at least three time points; determining a voltage frequency regulation manner based on the at least three sampling voltages; and dynamically regulating a voltage frequency of a power supply in the insulation impedance detection apparatus according to the voltage frequency regulation manner to obtain a voltage cycle of the power supply equal to an insulation time constant of the insulation impedance detection apparatus.

2. The frequency regulation method of claim 1, wherein determining the voltage frequency regulation manner based on the at least three sampling voltages comprises: determining that the voltage frequency regulation manner is maintaining the voltage frequency unchanged when the at least three sampling voltages meet a first function relationship; determining that the voltage frequency regulation manner is increasing the voltage frequency by a first step when the at least three sampling voltages do not meet the first function relationship but meet a second function relationship; or determining that the voltage frequency regulation manner is reducing the voltage frequency by a second step when the at least three sampling voltages do not meet the first function relationship but meet a third function relationship.

3. The frequency regulation method according to of claim 2, wherein the voltage cycle of the power supply in the insulation impedance detection apparatus is T, and wherein collecting sampling voltages at the sampling point for the at least three time points comprises: collecting a first sampling voltage at a first sampling point at a time point zero of the voltage cycle, collecting a second sampling voltage at a second sampling point at a time point T/4 of the voltage cycle, and collecting a third sampling voltage at a third sampling point at a time point T/2 of the voltage cycle, or collecting a first sampling voltage at a first sampling point at a time point T/2 of the voltage cycle, collecting a second sampling voltage at a second sampling point at a time point 3T/4 of the voltage cycle, and collecting a third sampling voltage at a third sampling point at a time point T of the voltage cycle.

4. The frequency regulation method of claim 3, wherein the first function relationship is $\frac{1}{2} (.Math. V_{3} .Math. + .Math. V_{1} .Math.) + \frac{k_{2}}{2} .Math. .Math. V_{3} .Math. - .Math. V_{1} .Math. .Math. < .Math. V_{2} .Math. < \frac{1}{2} (.Math. V_{3} .Math. + .Math. V_{1} .Math.) + \frac{k_{1}}{2} .Math. .Math. V_{3} .Math. - .Math. V_{1} .Math. .Math.,$ wherein the second function relationship is $.Math. V_{2} .Math. > \frac{1}{2} (.Math. V_{3} .Math. + .Math. V_{1} .Math.) + \frac{k_{1}}{2} .Math. .Math. V_{3} .Math. - .Math. V_{1} .Math. .Math.,$ wherein the third function relationship is $.Math. V_{2} .Math. < \frac{1}{2} (.Math. V_{3} .Math. + .Math. V_{1} .Math.) + \frac{k_{2}}{2} .Math. .Math. V_{3} .Math. - .Math. V_{1} .Math. .Math.,$ wherein V.sub.1 is the first sampling voltage, wherein V.sub.2 is the second sampling voltage, wherein V.sub.3 is the third sampling voltage, wherein k.sub.1∈(0,1), wherein k.sub.2∈(0,1), and wherein k.sub.2<k.sub.1.

6. A frequency regulation apparatus, applied to an insulation impedance detection apparatus in a direct current power system, comprising: a sampling unit configured to collect sampling voltages at a sampling point for at least three time points; a processing unit configured to determine a voltage frequency regulation manner based on the at least three sampling voltages; and a regulation unit configured to dynamically regulate a voltage frequency of a power supply in the insulation impedance detection apparatus according to the voltage frequency regulation manner to obtain a voltage cycle of the power supply equal to an insulation time constant of the insulation impedance detection apparatus.

7. The frequency regulation apparatus of claim 6, wherein the processing unit is further configured to: determine that the voltage frequency regulation manner is to maintain the voltage frequency unchanged when the at least three sampling voltages meet a first function relationship; determine that the voltage frequency regulation manner is to increase the voltage frequency by a first step when the at least three sampling voltages do not meet the first function relationship but meet a second function relationship; or determine that the voltage frequency regulation manner is to reduce the voltage frequency by a second step when the at least three sampling voltages do not meet the first function relationship but meet a third function relationship.

8. The frequency regulation apparatus of claim 7, wherein the voltage cycle of the power supply in the insulation impedance detection apparatus is T, and wherein the sampling unit is further configured to: collect a first sampling voltage at a first sampling point at a time point zero of the voltage cycle, collect a second sampling voltage at a second sampling point at a time point T/4 of the voltage cycle, and collect a third sampling voltage at a third sampling point at a time point T/2 of the voltage cycle, or collect a first sampling voltage at a first sampling point at a time point T/2 of the voltage cycle, a second sampling voltage at a second sampling point at a time point 3T/4 of the voltage cycle, and a third sampling voltage at a third sampling point at a time point T of the voltage cycle.

9. The frequency regulation apparatus of claim 8, wherein the first function relationship is $\frac{1}{2} (.Math. V_{3} .Math. + .Math. V_{1} .Math.) + \frac{k_{2}}{2} .Math. .Math. V_{3} .Math. - .Math. V_{1} .Math. .Math. < .Math. V_{2} .Math. < \frac{1}{2} (.Math. V_{3} .Math. + .Math. V_{1} .Math.) + \frac{k_{1}}{2} .Math. .Math. V_{3} .Math. - .Math. V_{1} .Math. .Math.$ wherein the second function relationship is $.Math. V_{2} .Math. > \frac{1}{2} (.Math. V_{3} .Math. + .Math. V_{1} .Math.) + \frac{k_{1}}{2} .Math. .Math. V_{3} .Math. - .Math. V_{1} .Math. .Math.,$ wherein the third function relationship is $.Math. V_{2} .Math. < \frac{1}{2} (.Math. V_{3} .Math. + .Math. V_{1} .Math.) + \frac{k_{2}}{2} .Math. .Math. V_{3} .Math. - .Math. V_{1} .Math. .Math.,$ wherein V.sub.1 is the first sampling voltage, wherein V.sub.2 is the second sampling voltage, wherein V.sub.3 is the third sampling voltage, wherein k.sub.1∈(0,1), wherein k.sub.2∈(0,1), and wherein k.sub.2<k.sub.1.

11. A frequency regulation apparatus, applied to an insulation impedance detection apparatus in a direct current power system, comprising: a memory comprising instructions; and a processor coupled to the memory and configured to execute the instructions, which cause the processor to be configured to: collect sampling voltages at a sampling point for at least three time points; determine a voltage frequency regulation manner based on the at least three sampling voltages; and dynamically regulate a voltage frequency of a power supply in the insulation impedance detection apparatus according to the voltage frequency regulation manner to obtain a voltage cycle of the power supply equal to an insulation time constant of the insulation impedance detection apparatus.

12. The frequency regulation apparatus of claim 11, wherein the processor is further configured to: determine that the voltage frequency regulation manner is maintaining the voltage frequency unchanged when the at least three sampling voltages meet a first function relationship.

13. The frequency regulation apparatus of claim 12, wherein the processor is further configured to: determine that the voltage frequency regulation manner is increasing the voltage frequency by a first step when the at least three sampling voltages do not meet the first function relationship but meet a second function relationship.

14. The frequency regulation apparatus of claim 12, wherein the processor is further configured to: determine that the voltage frequency regulation manner is reducing the voltage frequency by a second step when the at least three sampling voltages do not meet the first function relationship but meet a third function relationship.

15. The frequency regulation apparatus of claim 11, wherein the voltage cycle of the power supply in the insulation impedance detection apparatus is T.

16. The frequency regulation apparatus of claim 15, wherein the processor is further configured to collect a first sampling voltage at a first sampling point at a time point zero of the voltage cycle, collect a second sampling voltage at a second sampling point at a time point T/4 of the voltage cycle, and collect a third sampling voltage at a third sampling point at a time point T/2 of the voltage cycle.

17. The frequency regulation apparatus of claim 15, wherein the processor is further configured to collect a first sampling voltage at a first sampling point at a time point T/2 of the voltage cycle, collect a second sampling voltage at a second sampling point at a time point 3T/4 of the voltage cycle, and collect a third sampling voltage at a third sampling point at a time point T of the voltage cycle.

18. The frequency regulation apparatus of claim 11, wherein the processor is further configured to regulate the voltage frequency of the power supply in the insulation impedance detection apparatus further according to detection precision requirements.

19. The frequency regulation apparatus of claim 11, wherein the processor is further configured to regulate the voltage frequency of the power supply in the insulation impedance detection apparatus further according to detection duration requirements.

20. The frequency regulation apparatus of claim 11, wherein the at least three time points of the sampling point are set depending on a requirement.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows an insulation impedance detection apparatus in a direct current power system in the prior art;

(2) FIG. 2 is a schematic diagram of a manner of connection between a frequency regulation apparatus and an insulation impedance detection apparatus according to an embodiment of the present disclosure;

(3) FIG. 3 is a schematic flowchart of a frequency regulation method according to an embodiment of the present disclosure;

(4) FIG. 4(a) is a schematic diagram of a voltage of a power supply when the voltage of the power supply is a rectangular wave according to an embodiment of the present disclosure;

(5) FIG. 4(b) is a schematic diagram of a voltage at a sampling point when a voltage of a power supply is a rectangular wave according to an embodiment of the present disclosure;

(6) FIG. 5(a), FIG. 5(b), and FIG. 5(c) are schematic diagrams of distribution of a first sampling voltage, a second sampling voltage, and a third sampling voltage in different cases;

(7) FIG. 6 is a schematic flowchart of a frequency regulation method according to an embodiment of the present disclosure;

(8) FIG. 7 is a schematic flowchart of a frequency regulation method according to an embodiment of the present disclosure;

(9) FIG. 8(a) shows an insulation impedance detection apparatus, in a direct current power system, to which an embodiment of the present disclosure may be applied;

(10) FIG. 8(b) shows another insulation impedance detection apparatus, in a direct current power system, to which an embodiment of the present disclosure may be applied;

(11) FIG. 9 is a schematic diagram of a frequency regulation apparatus according to an embodiment of the present disclosure; and

(12) FIG. 10 is a schematic diagram of a hardware structure of a frequency regulation apparatus according to an embodiment of the present disclosure.

DETAILED DESCRIPTION

(13) To make the objectives, technical solutions, and advantages of the present disclosure clearer, the following further describes the present disclosure in detail with reference to the accompanying drawings.

(14) A frequency regulation method according to an embodiment of the present disclosure may be applied to an insulation impedance detection apparatus in a direct current power system. An insulation impedance detection apparatus in a direct current power system is shown in FIG. 1. Depicted is a device (or part) 100 under detection in the insulation impedance detection apparatus, and a detection part 110 in the insulation impedance detection apparatus. Device 100 includes a direct current power supply V.sub.B, an equivalent resistor Rbus between a positive electrode and a negative electrode of the direct current power supply, a capacitor Cbus between the positive electrode and the negative electrode, a resistor R.sub.p between the positive electrode and a reference ground, a capacitor C.sub.p between the positive electrode and the reference ground, a resistor Rn between the negative electrode and the reference ground, and a capacitor Rn between the negative electrode and the reference ground. Detection part 110 includes auxiliary detection resistors R.sub.1 and R.sub.2 and a power supply V.sub.sq.

(15) A connection manner between a frequency regulation apparatus and the insulation impedance detection apparatus in this embodiment of the present disclosure is shown in FIG. 2.

(16) FIG. 1 is used as an example to describe the frequency regulation method in this embodiment of the present disclosure.

(17) As shown in FIG. 3, the frequency regulation method in this embodiment of the present disclosure includes the following steps.

(18) Step 300: Collect sampling voltages at a sampling point at at least three time points.

(19) It should be noted that the sampling point may be set depending on a requirement. FIG. 1 is used as an example. A location between R1 and R2 may be used as the sampling point, or two ends of R2 may be used as sampling points, provided that a voltage at the sampling point being capable of varying with a change of parasitic capacitance can be reflected. Sampling time points of the sampling point are at least three time points that are set depending on an actual requirement. Sampling voltages at three time points are collected, for example, a first sampling voltage at a first time point, a second sampling voltage at a second time point, and a third sampling voltage at a third time point are collected.

(20) To more conveniently describe a relationship between a voltage frequency of a power supply and an insulation time constant by using a relationship between the first sampling voltage, the second sampling voltage, and the third sampling voltage, when a voltage cycle of the power supply in the insulation impedance detection apparatus is T, a first sampling voltage at the sampling point at a time point zero of the voltage cycle, a second sampling voltage at the sampling point at a time point T/4 of the voltage cycle, and a third sampling voltage at the sampling point at a time point T/2 of the voltage cycle are collected, or a first sampling voltage at the sampling point at a time point T/2 of the voltage cycle, a second sampling voltage at the sampling point at a time point 3T/4 of the voltage cycle, and a third sampling voltage at the sampling point at a time point T of the voltage cycle are collected.

(21) Step 301: Determine a voltage frequency regulation manner based on at least three sampling voltages obtained through sampling.

(22) Specifically, an optional implementation is determining whether the at least three sampling voltages obtained through sampling meet a first function relationship; and if it is determined that the at least three sampling voltages obtained through sampling meet a first function relationship, the voltage frequency regulation manner is maintaining the voltage frequency unchanged;

(23) when it is determined that the at least three sampling voltages obtained through sampling do not meet the first function relationship but meet a second function relationship, it is determined that the voltage frequency regulation manner is increasing the voltage frequency by a specified first step; or when it is determined that the at least three sampling voltages obtained through sampling do not meet the first function relationship but meet a third function relationship, it is determined that the voltage frequency regulation manner is reducing the voltage frequency by a specified second step.

(24) It should be noted that the first step and the second step may be set depending on an actual requirement, and the first step and the second step may be the same or may be different.

(25) Specifically, when the first sampling voltage at the sampling point at the time point zero of the voltage cycle, the second sampling voltage at the sampling point at the time point T/4 of the voltage cycle, and the third sampling voltage at the sampling point at the time point T/2 of the voltage cycle are collected, or when the first sampling voltage at the sampling point at the time point T/2 of the voltage cycle, the second sampling voltage at the sampling point at the time point 3T/4 of the voltage cycle, and the third sampling voltage at the sampling point at the time point T of the voltage cycle are collected, if the first function relationship is

(26) 0 $\frac{1}{2} (.Math. V_{3} .Math. + .Math. V_{1} .Math.) + \frac{k_{2}}{2} .Math. .Math. V_{3} .Math. - .Math. V_{1} .Math. .Math. < .Math. V_{2} .Math. < \frac{1}{2} (.Math. V_{3} .Math. + .Math. V_{1} .Math.) + \frac{k_{1}}{2} .Math. .Math. V_{3} .Math. - .Math. V_{1} .Math. .Math.,$
the second function relationship is

(27) $.Math. V_{2} .Math. > \frac{1}{2} (.Math. V_{3} .Math. + .Math. V_{1} .Math.) + \frac{k_{1}}{2} .Math. .Math. V_{3} .Math. - .Math. V_{1} .Math. .Math.,$
and the third function relationship is

(28) $.Math. V_{2} .Math. < \frac{1}{2} (.Math. V_{3} .Math. + .Math. V_{1} .Math.) + \frac{k_{2}}{2} .Math. .Math. V_{3} .Math. - .Math. V_{1} .Math. .Math.,$
where V.sub.1 is the first sampling voltage, V.sub.2 is the second sampling voltage, V.sub.3 is the third sampling voltage, k.sub.1∈(0,1), k.sub.2∈(0,1), and k.sub.2<k.sub.1; or if the first function relationship is |V.sub.3|−|V.sub.2|>ΔV.sub.a and |V.sub.2|−|V.sub.1|<ΔV.sub.b, the second function relationship is |V.sub.3|−|V.sub.2|<ΔV.sub.a, and the third function relationship is |V.sub.2|−|V.sub.0|<ΔV.sub.b, where V.sub.1 is the first sampling voltage, V.sub.2 is the second sampling voltage, V.sub.3 is the third sampling voltage, and ΔV.sub.a and ΔV.sub.b are constants that are not less than an absolute value of a detection error in voltage sampling.

(29) Step 302: Regulate a voltage frequency of a power supply in an insulation impedance detection apparatus according to the determined voltage frequency regulation manner.

(30) The frequency regulation method in this embodiment of the present disclosure may be performed by a separate microprocessor, may be performed by a microprocessor combined with an analog circuit, or may be separately performed by an analog circuit.

(31) When a voltage of the power supply Vsq is a rectangular wave voltage, and a voltage cycle of the power supply is T, the sampling point is set at a location 1 between R.sub.1 and R.sub.2 in FIG. 1, the first time point is a time point zero of the voltage cycle of the power supply Vsq, the second time point is a time point T/4 of the voltage cycle of the power supply Vsq, and the third time point is a time point T/2 of the voltage cycle of the power supply V.sub.sq. FIG. 4(a) and FIG. 4(b) are used as an example for description. FIG. 4(a) is a schematic diagram of a voltage waveform of the power supply. FIG. 4(b) is a voltage waveform diagram of a sampling point.

(32) When an insulation impedance R.sub.p is obtained through calculation by using the first sampling voltage V.sub.1, the second sampling voltage V.sub.2, and the third sampling voltage V.sub.3, to make R.sub.p obtained through calculation more accurate, an appropriate voltage frequency of a power supply V.sub.sq needs to be selected, so that a voltage half cycle of the power supply V.sub.sq is approximately equal to the insulation time constant.

(33) It is relatively difficult to regulate the voltage frequency of the power supply by directly measuring the insulation time constant. However, when a relationship between the voltage half cycle of the power supply and the insulation time constant affects the relationship between the sampling voltages V.sub.1, V.sub.2, and V.sub.3, the relationship between V.sub.1, V.sub.2, and V.sub.3 may indirectly reflect the relationship between the voltage half cycle of the power supply and the insulation time constant. Specifically, when the voltage half cycle of the power supply is far greater than the insulation time constant, a waveform graph of the sampling voltages V.sub.1, V.sub.2, and V.sub.3 at the sampling point is shown in FIG. 5(a). In this case, V.sub.2 is approximately equal to V.sub.3. When the voltage half cycle of the power supply is far less than the insulation time constant, a waveform graph of the sampling voltages V.sub.1, V.sub.2, and V.sub.3 at the sampling point is shown in FIG. 5(b). In this case, V.sub.1 is approximately an average value of V.sub.2 and V.sub.3. When the voltage half cycle of the power supply is approximately equal to the insulation time constant, a waveform graph of the sampling voltages V.sub.1, V.sub.2, and V.sub.3 at the sampling point is shown in FIG. 5(c).

(34) Therefore, the voltage frequency of the power supply may be regulated based on distribution of the sampling voltages V.sub.1, V.sub.2, and V.sub.3.

(35) When a sampling point is set at a location 1 between R1 and R2 shown in FIG. 1, and a voltage cycle of a power supply is T, as shown in FIG. 6, a frequency regulation method in an embodiment of the present disclosure includes the following steps.

(36) Step 600: Read a voltage frequency of a power supply in an insulation impedance detection apparatus.

(37) Step 601: For a voltage cycle T of the power supply, collect a first sampling voltage V.sub.1 at a sampling point at a time point zero of the voltage cycle, a second sampling voltage V.sub.2 at the sampling point at a time point T/4 of the voltage cycle, and a third sampling voltage V.sub.3 at the sampling point at a time point T/2 of the voltage cycle.

(38) Step 602: Determine whether V.sub.1, V.sub.2, and V.sub.3 obtained through sampling meet a first function relationship

(39) $\frac{1}{2} (.Math. V_{3} .Math. + .Math. V_{1} .Math.) + \frac{k_{2}}{2} .Math. .Math. V_{3} .Math. - .Math. V_{1} .Math. .Math. < .Math. V_{2} .Math. < \frac{1}{2} (.Math. V_{3} .Math. + .Math. V_{1} .Math.) + \frac{k_{1}}{2} .Math. .Math. V_{3} .Math. - .Math. V_{1} .Math. .Math.,$
where k.sub.1∈(0,1), k.sub.2∈(0,1), and k.sub.2<k.sub.1; and if V.sub.1, V.sub.2, and V.sub.3 obtained through sampling meet the first function relationship

(40) $\frac{1}{2} (.Math. V_{3} .Math. + .Math. V_{1} .Math.) + \frac{k_{2}}{2} .Math. .Math. V_{3} .Math. - .Math. V_{1} .Math. .Math. < .Math. V_{2} .Math. < \frac{1}{2} (.Math. V_{3} .Math. + .Math. V_{1} .Math.) + \frac{k_{1}}{2} .Math. .Math. V_{3} .Math. - .Math. V_{1} .Math. .Math.,$
perform step 603, or if V.sub.1, V.sub.2, and V.sub.3 obtained through sampling do not meet the first function relationship

(41) $\frac{1}{2} (.Math. V_{3} .Math. + .Math. V_{1} .Math.) + \frac{k_{2}}{2} .Math. .Math. V_{3} .Math. - .Math. V_{1} .Math. .Math. < .Math. V_{2} .Math. < \frac{1}{2} (.Math. V_{3} .Math. + .Math. V_{1} .Math.) + \frac{k_{1}}{2} .Math. .Math. V_{3} .Math. - .Math. V_{1} .Math. .Math.,$
perform step 604.

(42) Step 603: Determine that a voltage frequency regulation manner of the power supply in the insulation impedance detection apparatus is maintaining the voltage frequency of the power supply unchanged, and perform step 605.

(43) Step 604: If it is determined that V.sub.1, V.sub.2, and V.sub.3 obtained through sampling meet a second function relationship

(44) $.Math. V_{2} .Math. > \frac{1}{2} (.Math. V_{3} .Math. + .Math. V_{1} .Math.) + \frac{k_{1}}{2} .Math. .Math. V_{3} .Math. - .Math. V_{1} .Math. .Math.,$
determine that a voltage frequency regulation manner of the power supply is increasing the voltage frequency of the power supply by a specified first step; or if it is determined that V.sub.1, V.sub.2, and V.sub.3 obtained through sampling meet a third function relationship

(45) $.Math. V_{2} .Math. < \frac{1}{2} (.Math. V_{3} .Math. + .Math. V_{1} .Math.) + \frac{k_{2}}{2} .Math. .Math. V_{3} .Math. - .Math. V_{1} .Math. .Math.,$
determine that a voltage frequency regulation manner of the power supply is reducing the voltage frequency of the power supply by a specified second step.

(46) Step 605: Regulate the voltage frequency of the power supply in the insulation impedance detection apparatus according to the determined voltage frequency regulation manner.

(47) When a first sampling voltage V.sub.1 at the sampling point at a time point T/2 of the voltage cycle, a second sampling voltage V.sub.2 at the sampling point at a time point 3T/4 of the voltage cycle, and a third sampling voltage V.sub.3 at the sampling point at a time point T of the voltage cycle are collected, steps of a frequency regulation method are similar to steps shown in FIG. 6, and details are not described herein again.

(48) It should be noted that the first step and the second step may be set depending on an actual requirement, and the first step and the second step may be the same or may be different.

(49) An embodiment of the present disclosure further provides a frequency regulation method. As shown in FIG. 7, the method includes the following steps.

(50) Step 700: Read a voltage frequency of a power supply in an insulation impedance detection apparatus.

(51) Step 701: For a voltage cycle T of the power supply, collect a first sampling voltage V.sub.1 at a sampling point at a time point zero of the voltage cycle, a second sampling voltage V.sub.2 at the sampling point at a time point T/4 of the voltage cycle, and a third sampling voltage V.sub.3 at the sampling point at a time point T/2 of the voltage cycle.

(53) Step 703: Determine that a voltage frequency regulation manner of the power supply in the insulation impedance detection apparatus is maintaining the voltage frequency of the power supply unchanged, and perform step 705.

(54) Step 704: If it is determined that V.sub.1, V.sub.2, and V.sub.3 obtained through sampling meet a second function relationship |V.sub.3|−|V.sub.2|>ΔV.sub.a determine that a voltage frequency regulation manner of the power supply is increasing the voltage frequency of the power supply by a specified first step; or if it is determined that V.sub.1, V.sub.2, and V.sub.3 obtained through sampling meet a third function relationship |V.sub.2|−|V.sub.0|<ΔV.sub.b, determine that a voltage frequency regulation manner of the power supply is reducing the voltage frequency of the power supply by a specified second step.

(55) Step 705: A frequency regulation apparatus regulates the voltage frequency of the power supply in the insulation impedance detection apparatus according to the determined voltage frequency regulation manner.

(56) When a first sampling voltage V.sub.1 at the sampling point at a time point T/2 of the voltage cycle, a second sampling voltage V.sub.2 at the sampling point at a time point 3T/4 of the voltage cycle, and a third sampling voltage V.sub.3 at the sampling point at a time point T of the voltage cycle are collected, steps of a frequency regulation method are similar to steps shown in FIG. 7, and details are not described herein again.

(57) In addition, a frequency regulation method used when sampling points are at two ends of R2 shown in FIG. 1, that is, a sampling voltage is a voltage between the two ends of R2, is similar to the frequency regulation method used when the sampling point is at the location 1 between R1 and R2 shown in FIG. 1, and details are not described herein again.

(58) There are a plurality of manners for implementing the insulation impedance detection apparatus, which may be further shown in FIG. 8(a) and FIG. 8(b). A voltage frequency of a power supply may also be regulated by using the frequency regulation methods in the embodiments of the present disclosure. It should be noted that an application of the frequency regulation methods in the embodiments of the present disclosure is not limited to the insulation impedance detection apparatuses shown in FIG. 1, FIG. 8(a), and FIG. 8(b).

(59) In actual application, a specific first function relationship may be further set based on a specific sampling point.

(60) In addition, it should be noted that besides the foregoing embodiments, according to the frequency regulation methods in the embodiments of the present disclosure, a voltage frequency of a power supply may be further regulated depending on different detection precision requirements or different detection duration requirements.

(61) For example, when a direct current power system is in an initial startup process and requires insulation impedance detection to respond quickly, to avoid a hazard caused by a poor insulation status during startup, a lower requirement for insulation impedance detection precision may be set, and detection duration may be required to be short enough. In this case, the voltage frequency of the power supply may be increased by adjusting values of k1 and k2 in the present disclosure. When the direct current power system is in a running process and insulation resistance is near an alarm value, to avoid erroneous reporting, a higher requirement for resistance detection precision may be set, and detection duration may be allowed to be prolonged. In this case, the voltage frequency of the power supply may be reduced by adjusting values of k1 and k.sub.2 in the present disclosure.

(62) Based on a same inventive concept, an embodiment of the present disclosure further provides a frequency regulation apparatus. A method corresponding to the frequency regulation apparatus is the frequency regulation method in the embodiments of the present disclosure. Therefore, for implementation of the frequency regulation apparatus in this embodiment of the present disclosure, refer to implementation of the method, and repeated details are not described.

(63) As shown in FIG. 9, the frequency regulation apparatus in this embodiment of the present disclosure is applied to an insulation impedance detection apparatus in a direct current power system, and includes a sampling unit 900, a processing unit 901, and a regulation unit 902. The sampling unit 900 is configured to collect sampling voltages at a sampling point at at least three time points. The processing unit 901 is configured to determine a voltage frequency regulation manner based on the sampling voltages, obtained through sampling, at the at least three time points. The regulation unit 902 is configured to regulate a voltage frequency of a power supply in the insulation impedance detection apparatus according to the determined voltage frequency regulation manner.

(64) Optionally, the processing unit 901 is specifically configured to: when the at least three sampling voltages obtained through sampling meet a first function relationship, determine that the voltage frequency regulation manner is maintaining the voltage frequency unchanged; when the at least three sampling voltages obtained through sampling do not meet the first function relationship but meet a second function relationship, determine that the voltage frequency regulation manner is increasing the voltage frequency by a specified first step; or when the at least three sampling voltages obtained through sampling do not meet the first function relationship but meet a third function relationship, determine that the voltage frequency regulation manner is reducing the voltage frequency by a specified second step.

(65) Optionally, the sampling unit 900 is specifically configured to collect sampling voltages at the sampling point at three time points: a first sampling voltage at a first time point, a second sampling voltage at a second time point, and a third sampling voltage at a third time point.

(66) Optionally, a voltage cycle of the power supply in the insulation impedance detection apparatus is T; and the sampling unit 900 is specifically configured to: collect a first sampling voltage at the sampling point at a time point zero of the voltage cycle, a second sampling voltage at the sampling point at a time point T/4 of the voltage cycle, and a third sampling voltage at the sampling point at a time point T/2 of the voltage cycle, or collect a first sampling voltage at the sampling point at a time point T/2 of the voltage cycle, a second sampling voltage at the sampling point at a time point 3T/4 of the voltage cycle, and a third sampling voltage at the sampling point at a time point T of the voltage cycle.

(67) Optionally, the first function relationship is

(68) $\frac{1}{2} (.Math. V_{3} .Math. + .Math. V_{1} .Math.) + \frac{k_{2}}{2} .Math. .Math. V_{3} .Math. - .Math. V_{1} .Math. .Math. < .Math. V_{2} .Math. < \frac{1}{2} (.Math. V_{3} .Math. + .Math. V_{1} .Math.) + \frac{k_{1}}{2} .Math. .Math. V_{3} .Math. - .Math. V_{1} .Math. .Math.;$
the second function relationship is

(69) $.Math. V_{2} .Math. > \frac{1}{2} (.Math. V_{3} .Math. + .Math. V_{1} .Math.) + \frac{k_{1}}{2} .Math. .Math. V_{3} .Math. - .Math. V_{1} .Math. .Math.;$
and the third function relationship is

(70) 0 $.Math. V_{2} .Math. < \frac{1}{2} (.Math. V_{3} .Math. + .Math. V_{1} .Math.) + \frac{k_{2}}{2} .Math. .Math. V_{3} .Math. - .Math. V_{1} .Math. .Math.,$
where V.sub.1 is the first sampling voltage, V.sub.2 is the second sampling voltage, V.sub.3 is the third sampling voltage, k.sub.1∈(0,1), k.sub.2∈(0,1), and k.sub.2<k.sub.1.

(72) The sampling unit 900, the processing unit 901, and the regulation unit 902 may be integrated into one microprocessor during specific hardware implementation, to regulate the voltage frequency of the power supply together. Alternatively, the sampling unit 900, the processing unit 901, and the regulation unit 902 each may be an analog circuit that can perform a corresponding function, or one or two of the sampling unit 900, the processing unit 901, and the regulation unit 902 are implemented by using an analog circuit with a corresponding function, and one of the three units is implemented by using a microprocessor.

(73) FIG. 10 is a schematic hardware apparatus diagram of an implementation of a frequency regulation apparatus according to an embodiment of the present disclosure. The frequency regulation apparatus includes a processor 1000 and a memory 1100. The processor 1000 may be a general purpose central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, configured to execute a related program to implement the technical solution provided in the embodiments of the present disclosure. The memory 1100 may be a read only memory (ROM), a static storage device, a dynamic storage device, or a random access memory (RAM). The memory 1100 may store an operating system, another application, and operational data. When the technical solution provided in the embodiments of the present disclosure is implemented by using software or firmware, program code used to implement the technical solution provided in the embodiments of the present disclosure is stored in the memory 1100, and is executed by the processor 1000.

(74) In addition, depending on a specific requirement, persons skilled in the art should understand that the apparatus may further include a hardware component implementing another additional function. In addition, persons skilled in the art should understand that the device may alternatively include only a component or module necessary for implementing this embodiment of the present disclosure, and does not need to include all of the components shown in FIG. 10.

(75) It may be learned from the foregoing content that the frequency regulation method in the embodiments of the present disclosure is applied to the insulation impedance detection apparatus in the direct current power system, and includes: collecting the sampling voltages at the sampling point at the at least three time points; determining the voltage frequency regulation manner based on the sampling voltages, obtained through sampling, at the at least three time points; and regulating the voltage frequency of the power supply in the insulation impedance detection apparatus according to the determined voltage frequency regulation manner. According to this technical solution, the voltage frequency regulation manner of the power supply can be determined based on the at least three sampling voltages obtained through sampling, and the voltage frequency of the power supply can be regulated according to the determined voltage frequency regulation manner, so that an obtained voltage cycle of the power supply is approximately equal to an insulation time constant of the insulation detection apparatus. Therefore, precision of insulation impedance obtained by using sampling voltages at a regulated voltage frequency is relatively high, insulation impedance detection duration is reduced, and the voltage frequency of the power supply can be dynamically regulated when the parasitic capacitance changes, thereby avoiding a problem in the prior art that in order to improve precision of insulation impedance calculation, the insulation impedance detection duration is prolonged by setting the voltage frequency of the power supply to a relatively small value.

(76) Persons skilled in the art should understand that the embodiments of the present disclosure may be provided as a method, a system, or a computer program product. Therefore, the present disclosure may use a form of hardware only embodiments, software only embodiments, or embodiments with a combination of software and hardware. Moreover, the present disclosure may use a form of a computer program product that is implemented on one or more computer-usable storage media (including but not limited to a disk memory, a CD-ROM, an optical memory, and the like) that include computer-usable program code.

(77) The present disclosure is described with reference to the flowcharts and/or block diagrams of the method, the device (system), and the computer program product according to the embodiments of the present disclosure. It should be understood that computer program instructions may be used to implement each process and/or each block in the flowcharts and/or the block diagrams and a combination of a process and/or a block in the flowcharts and/or the block diagrams. These computer program instructions may be provided for a general purpose computer, a dedicated computer, an embedded processor, or a processor of another programmable data processing device to generate a machine, so that the instructions executed by the computer or the processor of another programmable data processing device generate an apparatus for implementing a specified function in one or more processes in the flowcharts and/or in one or more blocks in the block diagrams.

(78) These computer program instructions may alternatively be stored in a computer readable memory that can instruct a computer or another programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory generate an artifact that includes an instruction apparatus. The instruction apparatus implements a specified function in one or more processes in the flowcharts and/or in one or more blocks in the block diagrams.

(79) These computer program instructions may alternatively be loaded onto a computer or another programmable data processing device, so that a series of operations and steps are performed on the computer or the another programmable device, thereby generating computer-implemented processing. Therefore, the instructions executed on the computer or the another programmable device provide steps for implementing a specified function in one or more processes in the flowcharts and/or in one or more blocks in the block diagrams.

(80) Although some embodiments of the present disclosure have been described, persons skilled in the art can make changes and modifications to these embodiments once they learn the basic inventive concept. Therefore, the following claims are intended to be construed as covering the embodiments and all changes and modifications falling within the scope of the present disclosure.

(81) Obviously, persons skilled in the art can make various modifications and variations to the present disclosure without departing from the scope of the present disclosure. The present disclosure is intended to cover these modifications and variations made to the present disclosure, provided that they fall within the scope of protection defined by the following claims and their equivalent technologies.

Frequency regulation method and apparatus

Assignee

Inventors

Cpc classification

Classification Explorer

G01R27/025

PHYSICS

Classification Explorer

G01R27/04

PHYSICS

Classification Explorer

G01R35/005

PHYSICS

Classification Explorer

G01R27/18

PHYSICS

International classification

Classification Explorer

G01R27/18

PHYSICS

Classification Explorer

G01R35/00

PHYSICS

Classification Explorer

G01R27/02

PHYSICS

Classification Explorer

G01R27/04

PHYSICS

Abstract

Claims

Description