CN105717383B - The hot operating test device of the big component change current valve module of direct current transportation and its test method - Google Patents

Abstract

The invention relates to a test device for thermal operation of a converter valve module of a large direct current transmission component and a test method thereof. The device includes a converter valve module and saturated reactors connected to both ends of the converter valve module; the converter valve module includes A , B two groups of valve components; each group of valve components is composed of a saturated reactor and 15 grades of thyristors connected in series; each grade of thyristors is provided with a radiator; both ends of the saturated reactor are connected in parallel with diodes; the thyristor trigger mode The anode and gate of each thyristor are short-circuited with a small resistance resistor. The test method conducts the overall thermal operation test on the entire large-component converter valve, without changing the overall structure of the valve module, only slightly changing the electrical wiring of the tested converter valve module, replacing a small number of thyristor radiators and installing test busbars. The invention solves the problems of high test withstand voltage, large capacity of test AC power supply, limited test site and equipment caused by too many thyristor stages connected in series of large component converter valve modules.

Description

Test device and test method for thermal operation of converter valve module of large DC transmission components

technical field

The invention relates to a test device and a test method thereof in the technical field of ultra-high voltage direct current transmission, in particular to a test device for thermal operation of a converter valve module of a large component of direct current transmission and a test method thereof.

Background technique

The converter valve of the contemporary UHV DC transmission system is designed and constructed based on the principle of thyristor commutation. As an important power equipment and expensive asset in the country, once the DC transmission project is completed, it requires stable operation for more than decades. As the core of the DC transmission system The reliability test of the converter valve of the equipment is a necessary link when it leaves the factory. The thermal operation test for a single converter valve module is to pass the rated current to the thyristor of the module and measure the heating temperature of each thyristor to measure the cooling structure of the module. , Thyristor reliability evaluation test, this test can directly reflect the thermodynamic characteristics of the converter valve, and the test results can not only directly determine whether the product is qualified, but also can form the temperature records of all thyristors during the test. The unique "thermodynamic fingerprint" of Taiwan's converter valve provides the original basis for its online monitoring, operation and maintenance after it is put into operation.

The converter valve is composed of several valve modules, and each valve module includes a dozen to dozens of thyristors. The large-component converter valve referred to in this article refers to each valve module including dozens or more thyristors. At present, there is no thermal operation test scheme for this kind of large-component converter valve module in China. The original thermal operation test scheme is the thermal cycle test carried out by thyristor manufacturers when they conduct thyristor type tests: the test method is shown in Figure 1 As shown, 6 thyristors are connected in series as the tested product. The anode and gate of each thyristor are short-circuited, and a DC voltage is applied to both ends of the thyristor through a DC power supply. At the beginning of the test, the thyristor is triggered once and immediately conducts. After it is turned on, it will not be turned off, and the thyristor current will be changed by adjusting the DC power supply. This test method can conduct thermal running tests on a small number of thyristors, but for large-scale converter valve modules composed of dozens of thyristors connected in series, capacity and test voltage are required. Higher DC power supply, and the thyristors under test did not repeatedly trigger the commutation process. From the perspective of heating principle, due to the lack of recovery charge and switching loss links, its thermodynamic characteristics are not consistent with the actual situation of DC transmission projects.

Contents of the invention

Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a thermal operation test device and test method for large component converter valve modules of DC power transmission. There are problems such as high test withstand voltage, large capacity of test AC power supply, limited test site and equipment, etc., and ensure that the heating principle of the large component converter valve module in the thermal operation test is consistent with the actual project, so that the valve module has power frequency during the test process. commutation process.

The object of the present invention is to adopt following technical scheme to realize:

The invention provides a test device for thermal operation of a converter valve module of a large direct current transmission component. The improvement is that the device includes a converter valve module and saturable reactors connected to both ends of the converter valve module; the converter valve The module includes two groups of valve components A and B; each group of valve components is composed of a saturated reactor and 15 levels of thyristors in series; each level of thyristor is equipped with a radiator; the two ends of the saturated reactor are connected in parallel with freewheeling diodes; The thyristor is triggered by short-circuiting the anode and gate of each thyristor with a small resistance resistor.

The present invention also provides a test method for the thermal operation test device of the converter valve module of the DC transmission large component. The improvement is that the thermal operation test method includes: parallel connection; or (2) anti-parallel connection of two groups of 7-level thyristors in the converter valve module to realize the requirement of reducing the test power supply capacity; the resistance range of the small resistance resistor is 0.5-20 ohms.

Further, before the thermal running test: Divide the 15-level thyristors of each group of valve components into two groups of 1 and 2, and weld the busbar on the radiator at the boundary of the two groups of thyristors; where: the adjacent saturated reactor contains 7-level thyristors The first group consists of A-1 group thyristor strings and B-1 group thyristor strings; the second group including 8-level thyristors consists of A-2 group thyristor strings and B-2 group thyristor strings.

Further, in the above ①, the busbar welded on the radiator of each valve assembly is connected with the busbar of the saturable reactor with a cable, and the A-1 thyristor string and the B-1 thyristor string are short-circuited; the A The saturated reactors of the two groups of valve assemblies in B and B are connected, and a high-current and low-voltage AC power supply is applied between the midpoints of the converter valve modules. At this time, the thyristor strings of the A-2 group and the B-2 group Thyristor string Two groups of 8-level thyristors are connected in anti-parallel for thermal operation test; when the voltage is in the positive half cycle, group A-2 thyristor strings are turned on, and when the voltage is in the negative half cycle, group B-2 thyristor strings are turned on;

Further, in the above ②, connect the busbars welded on the radiators of the A and B groups of valve assemblies with cables, and short-circuit the thyristor strings of the A-2 group and the B-2 group of thyristor strings; connect the A and B groups The saturable reactor of the valve assembly is connected, and an AC power supply with high current and low voltage (high current range: 500-5000 amperes; low voltage range: 5-100 volts) is applied between the midpoints of the converter valve module, at this time The A-1 thyristor string of the converter valve module and the B-1 thyristor string two groups of 7-level thyristors are connected in antiparallel for thermal operation test; when the voltage is in the positive half cycle, the A-1 thyristor string conducts; when the voltage is in During the negative half cycle, the thyristor strings of group B-1 are turned on.

Further, the thermal running test includes the following steps: (1) short-circuiting the thyristor anode and gate with a small resistance resistor; (2) adjusting the AC power supply voltage; (3) triggering the thyristor, and the current reaches the expected value;

The high current range is 500-5000 amperes; the low voltage range is 5-100 volts.

Compared with the closest prior art, the beneficial effects that the present invention has are:

1) The thermal operation test device and test method of the converter valve module of the DC power transmission large component and the test method can solve the problem caused by the excessive number of thyristors of the converter valve module under the condition that the test site and the capacity of the power supply are limited. Difficulties in the test: This test method does not need to disassemble the converter valve module, only needs to slightly handle the equipment wiring, change a small number of radiators and install test busbars, and then the entire large-component converter valve module can be integrated. Hot running test.

2) The thermal operation test device and test method of the converter valve module of the DC power transmission large component provided by the present invention enable the valve module to have a thyristor power frequency commutation process during the thermal operation test, and the heat emitted by the thyristor is composed of not only the on-state The loss, as well as the switching loss, are closer to the actual engineering operating conditions, and the test data is more reliable.

3) When conducting the overall thermal operation test for the entire large-component converter valve module, it is not necessary to change the overall structure of the converter valve module, but only change a small amount of electrical wiring and radiators of the tested module and install the test method of the busbar;

4) Two groups of positive and negative anti-parallel thyristor strings are used to improve the utilization rate of AC power supply, so that the positive and negative half cycles of the AC voltage can be tested simultaneously on two sets of anti-parallel thyristor strings, and the test of making the series thyristor stage have a power frequency commutation process method;

5) The test method of installing a parallel diode on the saturable reactor of the valve module: provide a continuous flow path for the current of the converter valve module, suppress the sudden rise of the voltage at both ends of the inductance caused by the sudden interruption of the saturated reactor current, and avoid damage to the test equipment. and test personnel.

Description of drawings

Figure 1 is a schematic diagram of a 6-stage thyristor series thermal cycle test;

Fig. 2 is the electrical principle diagram of the thermal operation test of the 30-stage thyristor series converter valve module provided by the present invention, wherein (a) is a wiring diagram of A-2 group thyristor strings and B-2 group thyristor strings and two groups of 8-stage thyristor anti-parallel connections; (b) A-1 group of thyristor strings and B-1 group of thyristor strings are the anti-parallel connection diagrams of two groups of 7-level thyristor strings;

Fig. 3 is a volt-ampere characteristic diagram of one of the thyristors during the test under the thermal running test method provided by the present invention.

Detailed ways

The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings.

The invention provides a test scheme for thermal operation of a converter valve module of a UHV direct current transmission large component specially designed for tens of levels of thyristors connected in series. The invention can carry out the overall thermal operation test on the entire large component converter valve without changing the overall structure of the valve module, only needing to slightly change the electrical wiring of the tested converter valve module, replace a small number of thyristor radiators and install a test busbar , the whole test scheme is simple in principle and easy to implement. After the test is over, it is enough to restore the wiring of the tested converter valve and the changed components.

The invention provides a test device for thermal operation of a converter valve module of a large direct current transmission component. The device includes a converter valve module and saturable reactors connected to both ends of the converter valve module; , B, each group of valve components is composed of 15 thyristor stages in series, and each group of components is connected in series with a saturable reactor, so each valve module is composed of 30 thyristor stages and two saturable reactors in series. Each level of thyristor is equipped with a radiator; considering the freewheeling effect of the saturable reactor, in order to avoid high voltage hazards to equipment and personal safety, a freewheeling diode should be connected in parallel at both ends of the saturable reactor during the test, and the diode should be removed after the test . The triggering method of the thyristor is to directly short-circuit the anode and gate of each thyristor with a small resistance resistor. In this method, the voltage division of the thyristor is uniform, the turn-on and turn-off consistency of the thyristor is good, the wiring is simple, and it is easy to realize.

The present invention also provides a test method for the thermal operation test device of the converter valve module of the DC transmission large component. The busbar is welded on the radiator at the boundary of the group of thyristors, and the first group containing 7-level thyristors near the saturated reactor is the first group, which are respectively A-1 group thyristor strings and B-1 group thyristor strings; the second group contains 8-level thyristors, They are A-2 groups of thyristor strings and B-2 groups of thyristor strings. Before the test, replace the original radiator with the radiator with the busbar. After the test, remove the radiator with the busbar and replace it with the original radiator.

The test methods for the two groups of components are as follows:

1) In the first group of tests, the test wiring diagram is shown in Figure 2(a): Connect the busbar welded on the radiator in the middle part of each valve assembly to the busbar of the saturated reactor with a cable, and A-1 , B-1 two groups of thyristors are short-circuited. Connect the saturable reactors of the two valve assemblies together, and apply a high-current and low-voltage AC power supply between this point and the midpoint of the entire valve module. At this time, two valves A-2 and B-2 in the middle of the valve module 8-level thyristors are connected in series and anti-parallel for thermal operation test. Since the AC power supply is used in the test, when the voltage is in the positive half cycle, the thyristors of group A-2 are turned on, and when the voltage is in the negative half cycle, the thyristors of group B-2 are turned on.

2) In the second group of tests, the test wiring diagram is shown in Figure 2(b): connect the bus bars welded on the radiators in the middle of the two valve assemblies with cables, and connect the two groups of thyristors A-2 and B-2 Short it out. Also connect the saturable reactors of the two valve components, and apply a high-current and low-voltage AC power supply between these two points. At this time, the valve module is close to the two 7-stage thyristor strings A-1 and B-1 of the saturable reactor. Anti-parallel connection, thermal running test. When the voltage is in the positive half cycle, the thyristors of group A-1 are turned on; when the voltage is in the negative half cycle, the thyristors of group B-1 are turned on.

The thermal running test comprises the following steps: (1) short-circuiting the thyristor anode and the gate with a small resistance resistor; (2) adjusting the AC power supply voltage; (3) triggering the thyristor, and the current reaches the expected value;

The high current range is 500-5000 amperes; the low voltage range is 5-100 volts.

As shown in Figure 3, it is the volt-ampere characteristic diagram of one of the thyristors when the test is carried out under the thermal running test method proposed by the present invention. The current waveform IVT flowing through the thyristor is shown by the dashed line, and the thyristor is shown by the solid line. The terminal voltage UVT of the thyristor, where the t1 interval is the turn-on loss interval of the thyristor, the t2 interval is the turn-off loss interval of the thyristor, and the t3 interval is the conduction loss interval of the thyristor.

The thyristor actually works in the self-rectification state during the test: the thyristor component of the tested product is not only a half-wave rectifier bridge, but also a load. In this way, compared with the thermal operation test scheme involved in Figure 1, the system is equivalent to integrating the DC power supply and the tested product into the tested product itself, so the system performance can be doubled, and the capacity requirements for the test power supply Can be reduced by 50%.

The thermal operation test method involved in the present invention has already been applied in engineering practice. In the DC converter valve technical transformation project implemented by the unit, according to the user's requirements, some components of the thyristor level of the replacement valve module were provided. service, the user’s original converter valve is a large component converter valve module, each module includes 30-level thyristors, as shown in Figure 2 is a simplified schematic diagram of the thyristor series connection. After technical transformation, it is necessary to carry out thermal operation test. The unit proposes the test method described in the present invention in combination with the actual situation, and conducts a test on the valve module after technical transformation. According to the feedback from the user, this test scheme has a great impact on the thermal operation capacity of the converter valve. Fully verified, the test effect is ideal.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art can still implement the present invention Any modification or equivalent replacement that does not deviate from the spirit and scope of the present invention is within the protection scope of the claims of the pending application of the present invention.

Claims (1)

1. A test method for a thermal operation test device of a converter valve module of a direct current transmission large component, characterized in that the method uses a thermal run test device of a converter valve module of a large DC transmission component, and the device includes a converter valve module and the saturable reactor connected at both ends of the converter valve module; the converter valve module includes two groups of valve assemblies A and B; each group of valve assemblies is composed of a saturated reactor and 15-stage thyristor in series; each stage of thyristor is equipped with A radiator; freewheeling diodes are connected in parallel at both ends of the saturable reactor; the triggering method of the thyristor is to short-circuit the anode and gate of each thyristor by using a small resistance resistor; The thermal operation test method includes: ① anti-parallel connection of two groups of 8-level thyristors in the converter valve module; or ② anti-parallel connection of two groups of 7-level thyristors in the converter valve module, so as to reduce the demand for test power supply capacity; The resistance range of the small resistance resistor is 0.5-20 ohms; Before the hot running test: Divide the 15-level thyristors of each group of valve components into 1 and 2 groups, and weld the busbar on the radiator at the boundary of the two groups of thyristors; among them: the 7-level thyristor near the saturated reactor is the first Groups, respectively A-1 thyristor strings and B-1 thyristor strings; 8-level thyristors are the second group, respectively A-2 thyristor strings and B-2 thyristor strings; In the above ①, connect the busbar welded on the radiator of each valve assembly to the busbar of the saturable reactor with a cable, and short-circuit the A-1 thyristor string and the B-1 thyristor string; The saturable reactors of the group valve components are connected, and a high-current low-voltage AC power supply is applied between the midpoints of the converter valve modules. At this time, the thyristor strings of A-2 and B-2 of the converter valve modules A group of 8-level thyristors are connected in anti-parallel for thermal operation test; when the voltage is in the positive half cycle, the A-2 group of thyristor strings are turned on, and when the voltage is in the negative half cycle, the B-2 group of thyristor strings are turned on; In the above ②, connect the bus bars welded on the radiators of the A and B groups of valve assemblies with cables, and short-circuit the thyristor strings of the A-2 group and the B-2 group of thyristor strings; connect the A and B groups of valve assemblies The saturated reactor is connected, and a high-current and low-voltage AC power supply is applied between the midpoints of the converter valve module. At this time, the thyristor strings of A-1 group and B-1 group of thyristor strings of the converter valve module are two sets of 7-level thyristors. Anti-parallel connection, thermal operation test; when the voltage is in the positive half cycle, the thyristor strings of group A-1 are turned on; when the voltage is in the negative half cycle, the thyristor strings of group B-1 are turned on; The thermal running test comprises the following steps: (1) short-circuiting the thyristor anode and the gate with a small resistance resistor; (2) adjusting the AC power supply voltage; (3) triggering the thyristor, and the current reaches the expected value; The high current range is 500-5000 amperes; the low voltage range is 5-100 volts.