CN103901300B - Switching operation test system of 10 kV parallel capacitor - Google Patents

Abstract

The invention belongs to the technical field of field tests of switching operation of a parallel capacitor, and particularly relates to a switching operation test system of a 10 kV parallel capacitor. The switching operation test system of the 10 kV parallel capacitor comprises a signal collecting module, a signal trigger control module and a signal processing module. The signal collecting module is used for collecting voltage and current signals in the switching operation process of the parallel capacitor. The signal trigger control module is used for synchronizing the potential of the signals collected by the signal collecting module, and triggering the signal processing module to collect data. The signal processing module collects and processes voltage and current data, and obtains transient state characteristic data in the switching operation process of the parallel capacitor. The switching operation test system of the 10 kV parallel capacitor can collect the transient state data of the collector and breaker side and the parallel capacitor side, the transient state change characteristics in the switching operation of the 10 kV parallel capacitor can be reflected more comprehensively and more accurately, and more favorable data support is provided for research of the operation transient state process of the 10 kV parallel capacitor.

Description

10kV Shunt Capacitor Switching Operation Test System

technical field

The invention belongs to the field test technical field of parallel capacitor switching operation test, and in particular relates to a 10kV parallel capacitor switching operation test system.

Background technique

In recent years, my country's requirements for power grid stability and power quality have become increasingly stringent. In order to improve the power factor of the power system, reduce power loss, and enhance the power supply capacity of the grid, a low-voltage shunt capacitor bank is often installed on the low-voltage side of the transformer in the substation to adjust the system voltage. At present, vacuum circuit breakers are generally used for 10kV shunt capacitors in existing substations, and failure accidents such as shunt capacitors and circuit breaker explosions often occur during switching operations of vacuum circuit breakers, and the hazards and consequences of failures are extremely serious. Therefore, it is of great significance to design a 10kV shunt capacitor operating transient test system to accurately obtain the characteristics of the operating transient process, which will help to explore the cause of the fault and propose corresponding preventive measures.

Existing shunt capacitor operation test systems or devices, such as the Chinese invention patent application No. 201210392809.4 "A Monitoring System and Monitoring Method for Shunt Power Capacitor Switching Process", which discloses a parallel power capacitor switching process Monitoring system and monitoring method, the system is composed of power quality monitoring terminal, data storage unit and capacitor switching process monitoring module, and describes the basic functions and technical content of the three main modules of power quality monitoring terminal, data storage unit and so on. Another example is the Chinese invention patent application "High Voltage Shunt Capacitor Online Monitoring Device" with application number 201310251583.0, which discloses a high voltage parallel capacitor online monitoring device, including a dual-channel acquisition module for collecting high voltage parallel capacitor devices, a data processing module, The alarm management module introduces the function and technical scheme of the module, and basically realizes the function of judging the operating state of the high-voltage shunt capacitor device.

The main disadvantages of the above patents are: ①Only limited to the on-line monitoring system or device for shunt capacitors, only the bus voltage can be measured, and transient data such as the power supply of the circuit breaker, the voltage on both sides of the load, the capacitor current, and the neutral point voltage cannot be obtained , so that it is impossible to accurately grasp the characteristics of the transient transition process of the 10kV shunt capacitor operation; ②Due to the limitation of the simulation software, the computer simulation can no longer reflect the actual operation situation. At present, there is no corresponding patent to guide the research on the transient test of 10kV shunt capacitor operation. Therefore, the invention is helpful to the development of the 10kV shunt capacitor operation transient test, and has extremely important significance for the research of the shunt capacitor operation transient test and the solution of practical problems.

Contents of the invention

In view of this, the present invention provides a 10kV shunt capacitor switching operation test system, which can obtain more detailed transient data and can more accurately reflect the characteristics of the 10kV shunt capacitor operation transient process.

The present invention solves the above technical problems by the following technical means:

10kV shunt capacitor switching operation test system, including

The signal acquisition module is used to acquire voltage and current signals during the switching operation of parallel capacitors,

The signal trigger control module performs potential synchronization on the signal collected by the signal acquisition module, and triggers the signal processing module to collect data;

The signal processing module collects and processes voltage and current data, and obtains transient characteristic data during switching operation of parallel capacitors.

Further, the signal acquisition module specifically includes

Capacitive voltage divider, used to collect the voltage signal during the switching operation of parallel capacitors;

The current sensor is used to collect the current signal during the switching operation of the shunt capacitor;

The signal conditioning unit is used for conditioning the current signal.

Further, the capacitive voltage divider collects the circuit breaker bus voltage, the circuit breaker power supply side voltage and the circuit breaker load side voltage at the circuit breaker side, and the shunt capacitor reactor voltage, capacitor voltage, and neutral point voltage signals at the shunt capacitor side ;

The current sensor collects the contact current at the circuit breaker side, and the capacitor current and lightning arrester current at the parallel capacitor side.

Further, the signal trigger control module specifically includes:

The ground potential synchronization unit is used to synchronize the voltage and current signals collected by the acquisition module to eliminate the ground potential difference between the signal acquisition channels;

The trigger unit triggers the signal processing module to collect data according to the trigger signal of the circuit breaker operation relay.

Further, the signal processing module includes:

Two data acquisition units, respectively used to collect current and voltage data according to the trigger unit signal;

The data processing unit processes the data collected by the data acquisition unit;

The data storage unit stores the data processed by the data processing unit.

Further, the data processing unit performs the following calculation on the data:

In the formula, I is the current, U is the voltage, C is the equivalent capacitance value of the capacitor in the 10kV parallel capacitor test circuit, and the unit is farad; when the calculation result satisfies A≥5, it is considered that the closing inrush current exceeds the warning value, and B When ≥4, it is determined that the operating overvoltage exceeds the warning value, and an alarm signal is issued.

Beneficial effects of the present invention: The 10kV shunt capacitor switching operation test system of the present invention can collect the transient data of both sides of the circuit breaker, the parallel capacitor and the neutral point, and can more comprehensively and accurately reflect the transient state of the 10kV shunt capacitor switching operation. The changing characteristics of the state process.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Figure 1 shows a schematic structural diagram of a 10kV shunt capacitor switching operation test system;

Fig. 2 shows a schematic diagram of the arrangement of signal measurement points in the 10kV shunt capacitor switching operation test system.

detailed description

The present invention will be described in detail below in conjunction with the accompanying drawings.

Referring to FIG. 1 , the 10kV shunt capacitor switching operation test system of this embodiment includes a signal acquisition module, a signal trigger control module and a signal processing module.

The signal acquisition module is used to acquire voltage and current signals during the switching operation of parallel capacitors, specifically including:

Capacitive voltage divider, used to collect the voltage signal during the switching operation of parallel capacitors;

The current sensor is used to collect the current signal during the switching operation of the shunt capacitor;

Referring to Fig. 2, the capacitive voltage divider collects the circuit breaker bus voltage on the circuit breaker side, the circuit breaker power supply side voltage and the circuit breaker load side voltage, and the shunt capacitor reactor voltage, capacitor voltage, neutral point voltage on the shunt capacitor side Voltage signal; the current sensor collects the contact current on the circuit breaker side, and the capacitor current and lightning arrester current on the parallel capacitor side.

The signal conditioning unit is used for conditioning the current signal.

The signal trigger control module performs potential synchronization on the signal collected by the signal acquisition module, and triggers the signal processing module to perform data acquisition, specifically including:

The ground potential synchronization unit is used to synchronize the voltage and current signals collected by the acquisition module to eliminate the ground potential difference between the signal acquisition channels;

The trigger unit triggers the signal processing module to collect data according to the trigger signal of the circuit breaker operation relay.

The signal processing module collects and processes voltage and current data, obtains transient characteristic data during switching operation of parallel capacitors, and can output characteristic data and waveforms, specifically including:

Two data acquisition units, respectively used to collect current and voltage data according to the trigger unit signal;

The data processing unit processes the data collected by the data acquisition unit;

The data storage unit stores the data processed by the data processing unit.

Operation transient state: see Figure 2, the experimental operation is the closing and opening operations of the test circuit breaker. The state of the capacitor can be analyzed according to the U ₄ , U ₅ , U ₆ , and I ₂ parameters. The phase-to-ground overvoltage of the reactor opening can be directly obtained from the U ₄ parameter, and the U ₅ parameter and I ₂ parameter can directly obtain the input voltage of the capacitor. At this time, the input transient characteristics such as closing phase-to-ground overvoltage and closing inrush current, among them: the formula for calculating the overvoltage between closing poles of the capacitor is U _CJ =U ₅ -U ₆ , and the formula for calculating the overvoltage between closing phases is U _5ab =U _5a -U _5b , U _5bc =U _5b -U _5c , U _5ca =U _5c -U _5a ; the circuit breaker status can be analyzed according to I ₁ , U ₂ , U ₃ parameters, and the test system can be calculated according to the parameter formula The characteristics of phase-to-ground overvoltage, phase-to-phase overvoltage, and overcurrent are obtained, among which: phase-to-ground overvoltage can be directly read from the U ₃ parameter, and the phase-to-phase overvoltage calculation formula between the high-voltage bushings of the circuit breaker is U _3ab =U _3a - U _3b , U _3bc =U _3b -U _3c , U _3ca =U _3c -U _3a . I ₁ Obtain the time when the circuit breaker current is generated or disappeared, and judge the contact action characteristics. For the opening operation, the calculation formula of the recovery voltage after the circuit breaker is opened is U _Ahf = U _2a -U _3a , U _Bhf =U _2b -U _3b , U _Chf =U _2c -U _3c can get the characteristics, and then analyze The characteristics of arc restrike time, frequency and duration can be compared and verified with the I ₁ parameter to obtain the contact action characteristics, the bus voltage fluctuation influence characteristics can be directly obtained from the U ₁ parameter, and the characteristics of the arrester action and action time can be obtained from the I ₃ parameter It can be obtained directly; the formula for calculating the overcurrent multiple is (C is the equivalent capacitance value of the capacitor in the 10kV parallel capacitor test circuit, the unit is f (Farad), I is the current, U is the voltage), the calculation formula of the overvoltage operation multiple is When the calculation result satisfies the conditions of A≥5 and B≥4, the system automatically determines that the closing inrush current or operating overvoltage is a dangerous quantity, which can easily cause damage or explosion of the circuit breaker or capacitor and send out an alarm signal.

Finally, it is noted that the above embodiments are only used to illustrate the technical solutions of the present invention without limitation. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be carried out Modifications or equivalent replacements without departing from the spirit and scope of the technical solution of the present invention shall be covered by the claims of the present invention.

Claims (1)

1. 10kV shunt capacitor switching operation test system, characterized by: including The signal acquisition module is used to acquire the voltage and current signals during the switching operation of the shunt capacitor; The signal trigger control module performs potential synchronization on the signal collected by the signal acquisition module, and triggers the signal processing module to collect data; The signal processing module collects and processes voltage and current data to obtain transient characteristic data during the switching operation of parallel capacitors; The signal acquisition module specifically includes Capacitive voltage divider, used to collect the voltage signal during the switching operation of parallel capacitors; The current sensor is used to collect the current signal during the switching operation of the shunt capacitor; The signal conditioning unit is used to condition the current signal; The capacitive voltage divider collects circuit breaker bus voltage, circuit breaker power supply side voltage and circuit breaker load side voltage on the circuit breaker side, and parallel capacitor reactor voltage, capacitor voltage and neutral point voltage signals on the parallel capacitor side; The current sensor collects the contact current on the side of the circuit breaker, the capacitor current on the side of the parallel capacitor and the operating current of the arrester; The signal trigger control module specifically includes: The ground potential synchronization unit is used to synchronize the voltage and current signals collected by the signal acquisition module to eliminate the ground potential difference between the signal acquisition channels; The trigger unit triggers the signal processing module to collect data according to the trigger signal of the circuit breaker operation relay; The signal processing module includes: Two data acquisition units, respectively used to collect current and voltage data according to the trigger unit signal; The data processing unit processes the data collected by the data acquisition unit; The data storage unit stores the data processed by the data processing unit; The data processing unit performs the following calculations on the data: $\mathrm{<span\; class="notranslate">\; B</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; u</span>}<span\; class="notranslate">\; /</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 10</span>}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; 10</span>}}^{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; \&times;</span>\sqrt{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; /</span>\sqrt{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ;</span>$ In the formula, A is the closing inrush transient characteristic data, B is the operating overvoltage transient characteristic data; I is the current, U is the voltage; C is the equivalent capacitance value of the capacitor in the 10kV parallel capacitor test circuit, the unit is farad ; When the calculation result satisfies A≥5, it is determined that the closing inrush current exceeds the warning value; when B≥4, it is determined that the operating overvoltage exceeds the warning value, and an alarm signal is issued.