CN112051484A - Low-voltage direct-current system single-end fault location method based on voltage balancer - Google Patents
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- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/08—Locating faults in cables, transmission lines, or networks
- G01R31/081—Locating faults in cables, transmission lines, or networks according to type of conductors
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- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
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Abstract
The invention relates to a low-voltage direct-current system single-end fault location method based on a voltage balancer, which comprises the following steps: the low-voltage direct-current system configuration protection acts after a fault is detected, all IGBTs in the VSC converter and the voltage balancer are turned off, direct-current circuit breakers on two sides of the system act to cut off a fault line, and power transmission of the fault line is stopped; controlling the on-off of an IGBT in an opposite-end voltage balancer of the distance measuring device according to the fault type; the method comprises the steps that a distance measuring device is put into, the state of the distance measuring device is judged according to fault types, the distance measuring device comprises two direct current power supplies which are connected in series and can freely switch in polarity, and the polarity of the power supplies is switched according to the closing of different switches; different fault conditions form different distance measuring loops through controlling the distance measuring device and the voltage balancer; and (6) ranging.
Description
Technical Field
The invention belongs to the field of fault location of low-voltage direct-current systems.
Background
In recent years, the development of dc power supply technology has been greatly advanced, driven by the technological advantages of power electronics. Compared with the traditional alternating current power supply system, the low-voltage direct current power supply system has the advantages of strong transmission capability, small loss and high electric energy quality. Meanwhile, the low-voltage direct-current system is flexible to control, the problems of synchronization and stability do not need to be considered, and the access of a distributed power supply is facilitated. Based on the above advantages, the low voltage dc system has become the trend of future development of the power distribution network. Especially, the symmetrical monopole power supply system based on the voltage balancer is widely applied to the low-voltage direct-current power supply system due to the characteristics of simple structure, no influence of load unbalance and the like. In order to ensure the safe and stable operation of the low-voltage direct-current system, fault location must be performed quickly and accurately after a short-circuit fault occurs in a line. Therefore, the research on the fault location method applicable to the low-voltage direct-current system has important significance for improving the reliability of direct-current power supply
At present, scholars at home and abroad have carried out a great deal of research work on the method in the field of fault location of low-voltage direct-current systems. The existing distance measurement method of the direct current power distribution system can be divided into single-end distance measurement and double-end distance measurement according to whether communication is needed or not. The traditional R-L model algorithm variable acquisition mode is optimized by improving an R-L distance measurement method, a single-end distance measurement method suitable for a direct-current power distribution system is provided, a certain calculation error is reduced, and the numerical stability is improved. But the influence of transition resistance is not considered, and the method has certain limitation. The active injection method utilizes differential protection to monitor faults, and utilizes a probe power element to actively inject signals to position the faults after the breaker acts, so that a new idea is provided for direct current distance measurement. The norm analysis method starts from the traditional R-L theory, data estimation based on polynomial difference is introduced, and the measurement time with small estimation error interference is found through the analysis of the 1 norm, so that the defect of insufficient data required by single-ended distance measurement is effectively overcome. Generally, the traditional single-end distance measurement method has certain limitations because the traditional single-end distance measurement method cannot accurately measure distance due to the influence of transition resistance and the loss of end quantity. The ranging method based on the double-end information can effectively overcome the defect of the single-end ranging method. The double-end capacitance measurement method effectively eliminates the influence of transition resistance by collecting the capacitance change of the two outlet sides of the direct-current power distribution network under the fault condition. However, the ranging method based on communication may significantly increase the construction cost of the low voltage power distribution system, and may also cause data deviation due to clock asynchronism, even cause communication failure. Therefore, the research on a reliable and accurate single-ended distance measurement method is still an urgent problem to be solved for the stable operation of the power grid.
Disclosure of Invention
The invention provides a voltage balancer-based single-ended fault location method for a low-voltage direct-current system, which mainly aims at the problem that accurate fault location cannot be realized only by single-ended data due to the influence of transition resistance and loss of terminal quantity in the field of fault location of the low-voltage direct-current system. The technical scheme is as follows:
a low-voltage direct-current system single-end fault location method based on a voltage balancer comprises the following steps:
1) the low-voltage direct-current system configuration protection acts after a fault is detected, all IGBTs in the VSC converter and the voltage balancer are turned off, direct-current circuit breakers on two sides of the system act to cut off a fault line, and power transmission of the fault line is stopped.
2) Controlling the on-off of the IGBT in the opposite-end voltage balancer by the ranging device according to the fault type, and if the fault between the positive electrode and the negative electrode is judged to occur, maintaining the off state of the IGBT unchanged; the voltage balancer anode freewheeling diode is turned off due to the back voltage bearing, the ranging current forms a ranging loop through the cathode freewheeling diode, and if a single-pole-neutral line short circuit fault is judged to occur, the non-fault pole IGBT is controlled to be turned on;
3) the method comprises the steps that a distance measuring device is put into, the state of the distance measuring device is judged according to the fault type, the distance measuring device comprises two direct current power supplies which are connected in series and can freely switch in polarity, and the polarity of the power supplies is switched according to the closing of different switches; if the short-circuit fault between the positive electrode and the negative electrode is judged, the negative electrodes of the two direct-current power supplies of the distance measuring device are connected and serially connected into a fault line, and if the short-circuit fault between the positive electrode and the negative electrode of the two direct-current power supplies is judged to occur, the positive electrode and the negative electrode of the two direct-current power supplies of the distance measuring device are connected end to end;
4) different fault conditions form different distance measuring loops by controlling the distance measuring device and the voltage balancer, the distance measuring loops are solved by using kirchhoff's law, and fault distances and transition resistance expressions of the fault between the positive electrode and the negative electrode and the fault between the single electrode and the neutral line are respectively obtained:
when the positive and negative electrodes are in fault, the fault distance l and the transition resistance RfThe expressions are respectively:
at positive pole-short circuit earth fault, fault distance l and transition resistance RfThe expressions are respectively:
fault distance l and transition resistance R in case of negative-neutral short-circuit faultfThe expressions are respectively:
in the above formula, R1For the line length impedance, L represents the line length, x represents the proportion of the distance from the distance measuring device to the fault point to the line length, U1And U2Indicating the direct current supply of the distance measuring device, I1And I2Respectively are the current flowing through the positive and negative lines after the system is in a steady state;
5) after the distance measurement loop reaches a stable state, acquiring positive and negative pole current data of the distance measurement device through a power transformer, and performing noise reduction processing on the acquired current data through a moving average noise reduction method;
6) obtaining different fault types according to the fault pole selection result, substituting the current after noise reduction treatment into the fault distance expression of the corresponding fault type to obtain the fault distance l and transitionResistance RfSize.
The invention provides a low-voltage direct-current system single-end fault location method based on a voltage balancer, which forms a basic location loop by controlling devices in the voltage balancer after a fault. And then putting into an offline ranging device, and solving the fault distance and the transition resistance by only utilizing the local current magnitude to realize accurate positioning. The data required by positioning are measured under the direct current stable state, the influence of capacitance and inductance of a direct current line does not need to be considered, the defect that the information quantity of the traditional single-ended distance measurement is insufficient can be overcome only by local information, and the distance measurement without principle errors is realized. Compared with the prior art, the invention has the following advantages:
1. the method is simple, the direct current steady state data is used for distance measurement calculation, the influence of capacitance and inductance is not needed to be considered, and the distance measurement without principle errors can be realized only by using single-ended quantity. The distance measurement precision is high, and anti transition resistance ability reinforce can effectively resist the interference of noise simultaneously.
2. The method has the advantages of low cost and convenient realization of the ranging module. The distance measuring module can be repeatedly put into use, and has certain application value in engineering.
3. The method is not only suitable for a double-end power supply system, but also suitable for a ring-shaped or radial topological structure power supply system because the voltage balancer can be distributed at each point of the system.
Drawings
FIG. 1 is a schematic diagram of a low voltage DC system.
Fig. 2 is a schematic diagram of an inter-electrode short fault distance measurement loop.
Fig. 3 is a schematic diagram of a positive-neutral short-circuit fault distance measurement loop.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings.
1. The low-voltage direct-current system configuration protection acts rapidly after a fault is detected, all IGBTs in the VSC converter and the voltage balancer are turned off, direct-current circuit breakers on two sides of the system act to cut off a fault line, and power transmission of the fault line is stopped.
As shown in figure 1, a symmetrical monopole power supply mode is formed by adding a voltage balancer after the two-side AC/DC converter. The distance measuring device is installed at the initial end of the line on any side, and the distance measuring device is not put into use in a normal state. After a fault occurs, the ranging process can be divided into a fault control link and a ranging link according to the time sequence. And after detecting that the fault occurs, the system immediately enters a fault control link. First, the protection operation configured locally in the system is performed, and the dc breakers CB1 and CB2 disconnect the line, and the power transmission is terminated.
2. And controlling the on-off of the IGBT in the opposite-end voltage balancer of the distance measuring device according to the fault type.
If a fault between the positive electrode and the negative electrode occurs, the turn-off state of the IGBT is maintained unchanged. The voltage balancer anode freewheeling diode is turned off due to the back voltage bearing, and the ranging current forms a ranging loop through the cathode freewheeling diode. And if the single-pole neutral line short circuit fault occurs, controlling the non-fault pole IGBT to be conducted.
3. And judging the combination of switch inputs of the distance measuring device according to the fault type. If the fault is a short circuit fault between the positive electrode and the negative electrode, the distance measuring device is put into a state 1. State 2 is engaged when a unipolar-neutral short fault occurs.
DC Fault location Module topology As shown in FIG. 1, the location device consists of two identical DC power supplies and switches S0-S4. According to the difference of switch closure mode, direct current range finding module can divide into: an exit state, an access state 1 and an access state 2.
When S0 is closed and S1-S4 are opened, the distance measuring device exits the state; when the S0 is disconnected, the S1 is connected with the point A, the S2/S3 is connected with the point O, and the S4 is connected with the point D, the state is switched in 1; when S0 is disconnected, S1 is connected with point A, S2/S4 is connected with point O, and S3 is connected with point C, the state is switched on 2.
When the power grid normally operates, the distance measuring device works in an exit state, and the direct-current power distribution network carries out normal power transmission. After a fault occurs, the direct current breakers CB1 and CB2 act rapidly to cut off the line, and a direct current power supply is connected to carry out fault distance measurement. Specifically, when a short-circuit fault between a positive electrode and a negative electrode occurs, the distance measuring device works in a connection state 1. When a unipolar-neutral short-circuit fault occurs, the ranging device operates in the access state 2.
4. And modeling and analyzing different types of fault lines to obtain a fault distance formula.
4.1 short-circuit between positive and negative electrodes
When a short-circuit fault occurs between the positive and negative electrodes, the dc breaker operates rapidly to break the line, and then the distance measuring device is put into operation in the connected state 1, as shown in fig. 2 (a). After reaching a steady state, the opposite-end anode diode is turned off due to the back voltage, and the current forms a loop through the freewheeling diode of the opposite-end cathode voltage balancer, and the loop of the distance measuring structure is shown in fig. 2 (a). The equivalent circuit of the system at this time is shown in fig. 2 (b).
According to kirchhoff's law, the following can be obtained:
the following can be obtained:
namely, the distance between a fault point and the distance measuring device under the condition of short-circuit fault between the positive electrode and the negative electrode is as follows:
wherein R is1Is the impedance of the full length of the line, RfFor the transition resistance, L represents the total length of the line, x represents the proportion of the distance from the distance measuring device to the fault point to the total length of the line, and U1And U2Indicating the direct current supply of the distance measuring device, I1And I2The currents respectively flow through the positive pole line and the negative pole line after the system is in a steady state.
4.2 monopole-neutral short circuit fault
The single pole-neutral line short circuit fault indicates that one of the positive pole and the negative pole and the neutral line are in short circuit fault. Taking an anode-neutral line short circuit as an example, when a fault occurs, the fault control stage is firstly entered, the VSC converter and the voltage balancer IGBT are all locked, the system is configured with protection actions, and the direct current breaker cuts off a line. And then, each end of the line controls the negative electrode IGBT of the local end voltage balancer to be conducted. Subsequently, the ranging apparatus is put into the access state 2 as shown in fig. 3 (a). After the steady state is reached, the freewheeling diode of the fault pole of the opposite-end voltage balancer is turned off due to the back voltage, the current forms a loop through the IGBT of the non-fault pole, the structure of the ranging loop is shown in FIG. 3(a), and at the moment, the equivalent circuit of the system is shown in FIG. 3 (b).
According to kirchhoff's law, the following can be obtained:
simplifying the formula (5) to obtain:
namely, the distance between the fault point and the distance measuring device is as follows:
wherein R is1Is the impedance of the full length of the line, RfFor the transition resistance, L represents the total length of the line, x represents the proportion of the distance from the distance measuring device to the fault point to the total length of the line, and U1And U2Indicating the direct current supply of the distance measuring device, I1And I2The currents respectively flow through the positive pole line and the negative pole line after the system is in a steady state. Due to U1And U2Is a known amount, I1And I2Can be measured by a current transformer on the side of the distance measuring device, so that the fault distance can be measured under the condition of monopole-neutral short circuit faultThe result is obtained by equation (15).
Similarly, when the negative pole-neutral line short circuit fault occurs, the fault distance and the transition resistance are respectively as follows:
5. and a noise reduction algorithm is added to optimize the distance measurement method, so that errors caused by noise are reduced.
Because the time-domain characteristic of the noise is that the expected value is equal to zero, the algorithm can be anti-noised according to the characteristic. According to the method, firstly, the moving average method is selected to carry out preliminary noise reduction on the current data, and then the multiple distance measurement results are averaged, so that the influence of errors can be effectively reduced.
6. And after the distance measurement loop reaches a stable state, measuring the current of the single-ended positive and negative buses, and obtaining the fault distance according to a distance measurement formula.
And after the ranging loop reaches a stable state, substituting the current of the single-end positive and negative buses into a formula to calculate the fault distance according to different fault types. The positive and negative pole faults are substituted into a formula (10), the positive pole-neutral line short-circuit fault is substituted into a formula (14), and the negative pole-neutral line short-circuit fault is substituted into a formula (15).
Claims (2)
1. A low-voltage direct-current system single-end fault location method based on a voltage balancer comprises the following steps:
1) the low-voltage direct-current system configuration protection acts after a fault is detected, all IGBTs in the VSC converter and the voltage balancer are turned off, direct-current circuit breakers on two sides of the system act to cut off a fault line, and power transmission of the fault line is stopped.
2) Controlling the on-off of the IGBT in the opposite-end voltage balancer by the ranging device according to the fault type, and if the fault between the positive electrode and the negative electrode is judged to occur, maintaining the off state of the IGBT unchanged; the voltage balancer anode freewheeling diode is turned off due to the back voltage bearing, the ranging current forms a ranging loop through the cathode freewheeling diode, and if a single-pole-neutral line short circuit fault is judged to occur, the non-fault pole IGBT is controlled to be turned on;
3) the method comprises the steps that a distance measuring device is put into, the state of the distance measuring device is judged according to the fault type, the distance measuring device comprises two direct current power supplies which are connected in series and can freely switch in polarity, and the polarity of the power supplies is switched according to the closing of different switches; if the short-circuit fault between the positive electrode and the negative electrode is judged, the negative electrodes of the two direct-current power supplies of the distance measuring device are connected and serially connected into a fault line, and if the short-circuit fault between the positive electrode and the negative electrode of the two direct-current power supplies is judged to occur, the positive electrode and the negative electrode of the two direct-current power supplies of the distance measuring device are connected end to end;
4) different fault conditions form different distance measuring loops by controlling the distance measuring device and the voltage balancer, the distance measuring loops are solved by using kirchhoff's law, and fault distances and transition resistance expressions of the fault between the positive electrode and the negative electrode and the fault between the single electrode and the neutral line are respectively obtained:
5) after the distance measurement loop reaches a stable state, acquiring positive and negative pole current data of the distance measurement device through a power transformer, and performing noise reduction processing on the acquired current data through a moving average noise reduction method;
6) and obtaining different fault types according to the fault pole selection result, and substituting the current subjected to noise reduction treatment into a fault distance expression of the corresponding fault type to obtain the fault distance and the size of the transition resistor.
2. The method of claim 1, wherein:
when the positive and negative electrodes are in fault, the fault distance l and the transition resistance RfThe expressions are respectively:
positive electrode-short circuit groundAt fault, fault distance l and transition resistance RfThe expressions are respectively:
fault distance l and transition resistance R in case of negative-neutral short-circuit faultfThe expressions are respectively:
in the above formula, R1For the line length impedance, L represents the line length, x represents the proportion of the distance from the distance measuring device to the fault point to the line length, U1And U2Indicating the direct current supply of the distance measuring device, I1And I2The currents respectively flow through the positive pole line and the negative pole line after the system is in a steady state.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114062853A (en) * | 2021-11-19 | 2022-02-18 | 许昌许继软件技术有限公司 | Feeder line fault distance measurement method and device under compound line direct supply 50% standby mode |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005189005A (en) * | 2003-12-24 | 2005-07-14 | Honda Motor Co Ltd | Ground fault detection system |
| US9274161B1 (en) * | 2013-01-28 | 2016-03-01 | The Florida State University Research Foundation, Inc. | Voltage profile based fault location identification system and method of use |
| CN107064734A (en) * | 2017-03-17 | 2017-08-18 | 北京交通大学 | A kind of flexible direct current Fault Location for Distribution Network method of utilization fault transient process |
| CN108594067A (en) * | 2018-04-02 | 2018-09-28 | 湖南大学 | A kind of Multi-port direct-current distribution network line short fault distance measuring method |
| CN111521904A (en) * | 2019-11-15 | 2020-08-11 | 上海交通大学 | Direct-current distribution line double-end fault location method based on current harmonic quantity |
-
2020
- 2020-09-02 CN CN202010911544.9A patent/CN112051484A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005189005A (en) * | 2003-12-24 | 2005-07-14 | Honda Motor Co Ltd | Ground fault detection system |
| US9274161B1 (en) * | 2013-01-28 | 2016-03-01 | The Florida State University Research Foundation, Inc. | Voltage profile based fault location identification system and method of use |
| CN107064734A (en) * | 2017-03-17 | 2017-08-18 | 北京交通大学 | A kind of flexible direct current Fault Location for Distribution Network method of utilization fault transient process |
| CN108594067A (en) * | 2018-04-02 | 2018-09-28 | 湖南大学 | A kind of Multi-port direct-current distribution network line short fault distance measuring method |
| CN111521904A (en) * | 2019-11-15 | 2020-08-11 | 上海交通大学 | Direct-current distribution line double-end fault location method based on current harmonic quantity |
Non-Patent Citations (2)
| Title |
|---|
| YANG YACHAO等: "A fault location method suitable for low-voltage DC line[J].", 《IEEE TRANS ON POWER DELIVERY》 * |
| 张明: "多端柔性直流电网保护及稳定控制研究", 《中国优秀硕士学位论文全文数据库》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114062853A (en) * | 2021-11-19 | 2022-02-18 | 许昌许继软件技术有限公司 | Feeder line fault distance measurement method and device under compound line direct supply 50% standby mode |
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Application publication date: 20201208 |