CN104459236A - Bipolar linkage impulse current generator - Google Patents

Abstract

The invention provides a bipolar linkage impulse current generator, including a positive impulse current generator, a negative impulse current generator, a control system and a measurement system; the positive impulse current generator and the negative impulse current The generators are respectively provided with interfaces connected to the tested products, and are respectively connected to the control system through the discharge ball gap; the positive polarity impulse current generator and the negative polarity impulse current generator are controlled by the control system Discharge to the tested product in different time periods to generate impulse current; the measurement system measures and displays the voltage and current of the tested product. This kind of impulse current generator is economical and effective, and can generate two continuous impulse currents, one positive and one negative, with a controllable interval time, which is suitable for evaluating the energy tolerance of metal oxide voltage limiters.

Description

A Bipolar Linkage Impulse Current Generator

technical field

The invention relates to a current generator, in particular to an impulse current generator capable of simulating and generating a current waveform when a metal oxide voltage limiter for a series compensation device operates.

technical field

The energy tolerance of existing metal oxide voltage limiters is generally expressed by its energy tolerance under 2ms square wave current. This waveform can roughly simulate the current waveform under the operating overvoltage of a conventional AC system, and is used for Assess the energy tolerance of the arrester. However, the current waveform when the series compensation device operates with a metal oxide voltage limiter is very different from the 2ms square wave.

Figure 1 and Figure 2 show the current waveform of a typical metal oxide voltage limiter in action. Its main features are: when the AC system operates overvoltage, the impulse current flowing through the metal oxide voltage limiter is a plurality of continuous impulse currents, and the polarity of two adjacent impulse currents is opposite; the current waveform corresponds to the voltage waveform, The duration of the current is about 4ms, and the difference between the two current waveforms of opposite polarities is about half a power frequency cycle.

Therefore, in the traditional method, only using the energy tolerance of the metal oxide voltage limiter under the 2ms square wave current to represent its energy tolerance is obviously not accurate enough. It is necessary to provide a new technical solution to accurately simulate the current waveform when the metal oxide voltage limiter used in the series compensation device operates, and to assess the energy tolerance of the metal oxide voltage limiter.

Contents of the invention

In order to solve the above-mentioned problems existing in the prior art, the present invention provides an inrush current generator capable of simulating and generating a current waveform when a metal oxide voltage limiter for a series compensation device operates. Negative two continuous impulse currents with a controllable interval time are used to assess the energy tolerance of the voltage limiter.

The technical solution provided by the present invention is: a bipolar linkage surge current generator, including a positive polarity surge current generator, a negative polarity surge current generator, a control system and a measurement system; its improvement is: the positive polarity The impulse current generator and the negative polarity impulse current generator are respectively provided with an interface connected to the tested product, and are respectively connected to the control system through the discharge ball gap; the positive polarity impulse current generator is connected to the negative polarity Under the control of the control system, the impulse current generator discharges to the tested object at different time periods to generate impulse current; the measurement system measures and displays the voltage and current of the tested object.

Preferably, the control system includes an AC power supply, a thyristor, a thyristor controller, a transformer, a rectifier, a discharge system and a main controller;

The input terminal of the silicon controlled rectifier is connected to the alternating current, the output terminal thereof is connected to the input terminal of the transformer, the output terminal of the transformer is connected to the input terminal of the rectifier, and the output terminal of the rectifier is connected to the discharge system;

The main controller is connected to the control pole of the thyristor through a thyristor controller; and detects the output voltage of the rectifier through a voltage divider; the main controller sends a signal to the rectifier according to the output voltage of the rectifier The thyristor controller is configured to enable the thyristor controller to control the turn-on or turn-off of the thyristor, thereby adjusting the input voltage of the transformer;

The main controller is connected with the discharge system, and is used to control the discharge system to generate a high-voltage trigger pulse output to the discharge ball gap of the positive polarity impulse current generator or the isolation ball gap and discharge of the negative polarity surge current generator. ball clearance.

Further, the main controller controls the discharge time of the discharge ball gap and the isolation ball gap, and the discharge time is 2ms-10ms.

Preferably, the positive surge current generator includes a first charging device, an energy storage capacitor C1, an inductor L1, a first discharge ball gap and a resistor valve plate; the energy storage capacitor C1, the inductor L1, the first A discharge ball gap, the resistance valve plate, and the tested product are sequentially connected to form a closed loop;

The first charging device is connected in parallel with the energy storage capacitor C1; the connection terminal between the energy storage capacitor C1 and the DUT is grounded.

Further, the negative polarity surge current generator includes a second charging device, an energy storage capacitor C2, an inductor L2, a second discharge ball gap and an isolation ball gap; the energy storage capacitor C2, the inductor L2, the second discharge ball Gap, the spacer ball gap, and the tested product are connected in sequence to form a closed loop;

The second charging device is connected in parallel with the energy storage capacitor C2, and the connection terminal between the energy storage capacitor C2 and the DUT is grounded.

Further, the connecting end of the isolation ball gap and the second discharge ball gap is connected to one end of a clamping resistor, and the other end of the clamping resistor is grounded.

Further, the first charging device and the second charging device respectively charge the energy storage capacitor C1 with positive polarity electricity and the energy storage capacitor C2 with negative polarity electricity, and when the control system controls the discharge of the first discharge ball gap, the positive polarity surge current generator circuit conduction, the energy storage capacitor C1 discharges the tested product through the inductance L1, the first discharge ball gap, and the resistance valve plate;

After the discharge of the energy storage capacitor C1 is completed; the control system controls the discharge of the second discharge ball gap and the isolation ball gap, the negative polarity surge current generator circuit is turned on, and the energy storage capacitor C2 passes through the inductor L2, the second discharge ball The gap, and the isolation ball gap discharge the tested product.

Preferably, the measurement system includes a voltage divider, a shunt and an oscilloscope; the voltage divider is connected in parallel with the tested product, and is used to measure the voltage at both ends of the tested product, and output the measured voltage value to the tested product. The oscilloscope is used for waveform display;

The shunt is connected in series with the tested product, and is used to measure the current flowing through the tested product, and output the measured current value to an oscilloscope for waveform display.

Further, the oscilloscope is connected with the main controller of the control system by means of photoelectric conversion, and transmits the voltage and current signals of the tested product to the main controller, and the main controller calculates according to the voltage and current signals The energy absorbed by the test article.

Compared with the closest technical solution, the present invention has the following remarkable progress:

1) The technical solution provided by the present invention can economically and efficiently determine the energy tolerance of the metal oxide voltage limiter, and overcome the defects of large capacity requirements and poor controllability when using a power frequency circuit to realize the assessment.

2) The present invention isolates the ball gap in series in the circuit of the negative polarity surge current generator, and controls the discharge of the discharge ball gap through the control system, which can prevent the energy storage capacitor C1 of the positive polarity surge current generator from directly charging the negative electrode in practical applications. The malfunction of the discharge of the energy storage capacitor C2 of the impulse current generator.

3) The present invention can prevent the energy storage capacitor C2 of the negative polarity surge current generator from discharging through the positive polarity by connecting the resistance valve plate in series in the circuit of the positive polarity surge current generator, and controlling the discharge ball gap discharge through the control system. The surge current generator circuit shorts the current signal.

4) A clamping resistor is set in the circuit of the negative polarity impulse current generator to ensure that the circuit of the negative polarity impulse current generator can be ignited smoothly, and the reliability of the impulse current generator is improved.

5) The photoelectric conversion method is used to collect and transmit signals between the measurement system and the control system, which prevents the interference of high-voltage electromagnetic interference and ground potential in the system on the control signal.

Description of drawings

Figure 1 is a single-phase ground fault in a traditional series compensator device, the spark gap refuses to move, and the MOV voltage, current and energy consumption waveform diagram of the metal oxide voltage limiter;

Figure 2 is a three-phase ground fault in a traditional series compensator device, the spark gap refuses to move, and the MOV voltage, current and energy consumption waveform diagram of the metal oxide voltage limiter;

Fig. 3 is the schematic diagram of the bipolar surge current generator provided by the present invention;

Fig. 4 is the structural representation of control system of the present invention;

Fig. 5 is the structural representation of measuring system of the present invention;

FIG. 6 is a waveform diagram of voltage and current generated by the bipolar impulse current generator provided by the present invention.

Among them: 1-shunt, 2-voltage divider, 3-discharge ball gap 1, 4-discharge ball gap 2, 5-isolation ball gap, 6-clamp resistor, 7-tested product, 8-resistance valve .

Detailed ways

In order to better understand the present invention, the content of the present invention will be further described below in conjunction with the accompanying drawings and examples.

The bipolar linkage impulse current generator provided by the present invention is mainly composed of two sets of impulse current generators with opposite polarities, a control system, a protection system and a measurement system;

The circuit design of two sets of unipolar impulse current generators with opposite polarities is shown in Figure 3, mainly including:

A positive impulse current generator generating a positive waveform and a negative impulse current generator producing a negative waveform;

The positive polarity surge current generator includes energy storage capacitor C1, inductor L1, discharge ball gap 1 and resistance valve plate; energy storage capacitor C1, inductor L1, discharge ball gap 1, resistance valve plate, and the tested product are connected in sequence to form a closed Loop; the energy storage capacitor C1 is charged with positive polarity electricity through the charging equipment connected in parallel at its two ends, and its discharge is controlled by the control system to ignite the discharge ball gap 1;

The negative polarity surge current generator includes energy storage capacitor C2, inductor L2, discharge ball gap 2 and isolation ball gap; energy storage capacitor C2, inductor L2, discharge ball gap 2, isolation ball gap, and the tested product are sequentially connected to form a closed Loop; the energy storage capacitor C2 is charged with negative polarity electricity through the charging equipment connected in parallel at its two ends, and its discharge is controlled by the control system to ignite the discharge ball gap 2 and the isolation ball gap;

In actual use, the equipment is prone to malfunction such that the energy storage capacitor C1 of the positive surge current generator directly discharges the energy storage capacitor C2 of the negative polarity surge current generator. For this reason, the isolation ball gap and discharge system are used in the present invention 3 to reduce the malfunction of the system in this respect.

In addition, the non-linear resistance valve plate is connected in series in the circuit of the positive surge current generator, which can ensure that the energy storage capacitor C2 of the negative polarity surge current generator will not pass the current signal through the energy storage capacitor C1 of the positive polarity surge current generator. bypass.

The clamping resistor in the loop of the negative surge current generator is a resistance of MΩ level, which is used to provide the reference ground potential for the lower half of the discharge ball gap 2, so as to ensure that the loop of the negative polarity surge current generator can be ignited smoothly.

The control system is shown in Figure 4: the joint action of the positive and negative circuits with different polarities is controlled by the control system, the control system can control the discharge time of the two circuits with different polarities, and the discharge time is adjustable, flexible from 2mS to 10mS set up.

The control system mainly includes: 380V AC power supply, thyristor, thyristor controller, transformer, rectifier, discharge system and main controller;

The control loop adopts closed-loop control. The main controller (computer and PLC system) detects the output voltage of the rectifier through the voltage divider, and sends a signal to the thyristor controller according to the output voltage of the rectifier, so that the thyristor controller controls the thyristor. Turn on or off to adjust the input voltage of the transformer;

The main controller is connected with the discharge system, used to control the discharge system to generate high-voltage trigger pulse output to the discharge ball gap of the positive polarity impact current generator or the isolation ball gap and the discharge ball gap of the negative polarity surge current generator, to the discharge ball gap or Isolate ball gap ignition.

The measurement system is shown in Figure 5: the measurement system can measure positive polarity impulse current waveform, amplitude and corresponding voltage waveform, amplitude; negative polarity impulse current waveform, amplitude and corresponding voltage waveform, amplitude; positive and negative polarity Time interval, energy absorbed by the test object per impact, total energy;

The measurement system mainly includes a voltage divider, a shunt and an oscilloscope; the voltage divider is connected in parallel with the tested product to measure the voltage across the tested product; the shunt is connected in series with the tested product to measure the voltage flowing through the tested product. Current; the voltage and current waveforms measured by the voltage divider and shunt are displayed by an independent power supply oscilloscope;

The independent power supply oscilloscope is connected to the control system, sends the voltage and current of the tested product to the control system, and calculates the energy absorbed by the tested product through the control system.

The specific working process of the bipolar linkage impulse current generator is as follows:

The bipolar impulse current generator uses two sets of charging equipment to charge the positive polarity voltage to the capacitor C1 and charge the negative polarity voltage to the capacitor C2. When the voltage is charged to the set value, the control system sends a discharge signal to the discharge system 1, the circuit of the positive polarity impulse current generator is connected, and the discharge of capacitor C2 generates a positive half-wave impulse current waveform, and at the same time, the measurement system detects the discharge of the positive polarity circuit signal, and send it to the control system, the control system delays the signal, the delay time is adjustable from 2mS to 10mS, and then transmits the signal to the discharge system 2 and discharge system 3, and they act at the same time, so that the capacitor with negative polarity voltage is charged C2 discharges the tested product, thereby generating a negative polarity waveform to the tested product.

In order to prevent the interference of high-voltage electromagnetic interference and ground potential on the control signal in the system, the control system and the measurement system adopt photoelectric conversion to collect and transmit signals.

As shown in Figure 6: Figure 6 is the current and voltage waveform diagram of the bipolar impulse current generator. The upper part of the figure is the voltage signal, and the lower part is the current signal.

The above is only an embodiment of the present invention, and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention are all pending applications for the rights of the present invention. within the required range.

Claims (9)

1. a bipolarity interlock impulse current generator, comprises positive polarity impulse current generator, negative polarity impulse current generator, control system and measuring system; It is characterized in that: described positive polarity impulse current generator is respectively equipped with described negative polarity impulse current generator the interface be connected with product to be tested, and is connected with described control system respectively by ball discharge gap; Described positive polarity impulse current generator and described negative polarity impulse current generator discharge to described product to be tested in different time sections respectively, to produce dash current under the control of described control system; Described measuring system is measured and is shown the voltage and current of described product to be tested.

2. a kind of bipolarity interlock impulse current generator as claimed in claim 1, is characterized in that:

Described control system comprises AC power, controllable silicon, controllable silicon controller, transformer, rectifier, discharge system and master controller;

Described silicon controlled input end is connected with alternating current, and its output terminal is connected with the input end of described transformer, and the output terminal of described transformer is connected with the input end of rectifier, and the output terminal of described rectifier is connected with discharge system;

Described master controller controls pole by controllable silicon controller and described silicon controlled and is connected; And the output voltage of described rectifier is detected by voltage divider; Described master controller sends a signal to described controllable silicon controller according to the output voltage of described rectifier, makes described controllable silicon controller control described silicon controlled conducting or shutoff, thus regulates the input voltage of described transformer;

Described master controller is connected with discharge system, produces high pressure trigger pulse export the ball discharge gap of described positive polarity impulse current generator or the batching sphere gap of described negative polarity impulse current generator and ball discharge gap to for controlling described discharge system.

3. a kind of bipolarity interlock impulse current generator as claimed in claim 2, is characterized in that:

The discharge time of ball discharge gap described in described main controller controls and described batching sphere gap, described discharge time is 2ms-10ms.

4. a kind of bipolarity interlock impulse current generator as claimed in claim 1, is characterized in that:

Described positive polarity impulse current generator comprises the first charging equipment, storage capacitor C1, inductance L 1, first ball discharge gap and resistor valve sheet; Described storage capacitor C1, described inductance L 1, described first ball discharge gap, described resistor valve sheet and described product to be tested are in turn connected to form a closed-loop path;

Described first charging equipment is in parallel with described storage capacitor C1; The link ground connection of described storage capacitor C1 and described product to be tested.

5. a kind of bipolarity interlock impulse current generator as claimed in claim 4, is characterized in that:

Negative polarity impulse current generator comprises the second charging equipment, storage capacitor C2, inductance L 2, second ball discharge gap and batching sphere gap; Described storage capacitor C2, described inductance L 2, described second ball discharge gap, described batching sphere gap and described product to be tested are in turn connected to form a closed-loop path;

Described second charging equipment is in parallel with described storage capacitor C2, the link ground connection of described storage capacitor C2 and described product to be tested.

6. a kind of bipolarity interlock impulse current generator as claimed in claim 5, is characterized in that:

Described batching sphere gap is connected with one end of clamp resistance with the link of described second ball discharge gap, the other end ground connection of described clamp resistance.

7. a kind of bipolarity interlock impulse current generator as claimed in claim 6, is characterized in that:

First charging equipment and the second charging equipment fill positive polarity electricity to storage capacitor C1 respectively and fill negative polarity electricity to storage capacitor C2, when control system controls the first electric discharge ball-gap discharge, the loop conducting of positive polarity impulse current generator, described storage capacitor C1 is discharged to product to be tested by inductance L 1, first ball discharge gap and resistor valve sheet;

After described storage capacitor C1 has discharged; Described control system controls the second ball discharge gap and isolation ball-gap discharge, and the loop conducting of negative polarity impulse current generator, described storage capacitor C2 is discharged to described product to be tested by inductance L 2, second ball discharge gap and batching sphere gap.

8. a kind of bipolarity interlock impulse current generator as claimed in claim 1, is characterized in that:

Described measuring system comprises voltage divider, shunt and oscillograph; Described voltage divider is in parallel with described product to be tested, for measuring the voltage at described product to be tested two ends, and measuring voltage value is exported to described oscillograph carries out waveform display;

Described shunt is connected with described product to be tested, for measuring the electric current flowing through described product to be tested, and measurement current value is exported to oscillograph carries out waveform display.

9. a kind of bipolarity interlock impulse current generator as claimed in claim 8, is characterized in that:

Described oscillograph is connected with the master controller of control system by photoelectric conversion mode, give described master controller by the voltage and current Signal transmissions of described product to be tested, described master controller calculates the energy of described product to be tested absorption according to described voltage and current signal.