Rectifier valve of main network movable type direct current ice melting device

Abstract

The utility model belongs to the technical field of electric power facilities, and particularly discloses a rectifying valve of a main network movable type direct current ice melting device. Comprising a thyristor state detection module, a thyristor synchronous trigger module, a 12-pulse rectification circuit electrically connected with the DC ice melting device, and a thyristor control module in communication connection with a control protection system of the DC ice melting device. A static voltage-sharing resistor, a dynamic voltage-sharing resistor-capacitor and a fly-wheel diode are configured on each level of thyristor in each single valve in the 12-pulse rectification circuit, so that the average distribution of valve side voltage is realized; the thyristor synchronous trigger module further improves the trigger conduction consistency of the series thyristors in the single valve, and the phenomenon of non-uniform partial pressure caused by inconsistent conduction time of the thyristors is obviously reduced; by configuring the thyristor state detection module, the running state of the thyristor is detected in real time, fault information is found and uploaded in time, and the reliability of a core component of the rectifying valve and the whole direct-current ice melting device is improved. The method is suitable for occasions for controlling power input of the direct-current deicing device.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of electric power facilities, specifically discloses a main network mobile type direct current ice melting device rectifier valve. BACKGROUND

[0002] The harm caused by icing of overhead transmission lines is very serious, and often causes overloading, ice flash, dancing, ice shedding and jumping and other phenomena, leading to line tripping, wire breaking, tower collapse and communication interruption and other accidents, and ice disaster is one of the most serious hazards for safe operation of power grid. In recent years, power grid icing has obviously changed from occasional occurrence to normalization, and the anti-icing work of power grid is facing a great challenge.

[0003] There are various methods for ice melting and deicing, and direct current ice melting technology is a method for eliminating icing of transmission lines by applying direct current to the iced transmission lines through a direct current ice melting device to utilize the heating effect of the current. The direct current ice melting technology is considered as the most ideal one among existing ice melting methods due to its high efficiency, environmental protection, safety and flexibility.

[0004] The rectifier valve is a core component of the direct current ice melting device, and the fixed direct current ice melting device is generally configured for 500kV alternating current transmission line ice melting, and diodes are used as rectifier components; the mobile direct current ice melting device is generally configured for transmission lines below 220kV, and thyristor rectifier valves are used as rectifier components. Limited by semiconductor manufacturing process, the withstand voltage of a single thyristor is only several kilovolts, the rated direct current output voltage of the direct current ice melting device is generally 10-12kV, at the same time, the withstand voltage design of the thyristor valve should consider sufficient safety factor, including non-uniformity of voltage distribution, overvoltage protection level and the like, and the withstand voltage of the actual direct current ice melting device rectifier valve needs to reach several tens of kilovolts, therefore, each single valve in the rectifier needs to be composed of multiple thyristors in series.

[0005] In the production process of the thyristor, due to different materials and process methods, the parameters of each thyristor are dispersed, and the resistances of the thyristor in the on state and the off state are greatly different, if the turn-on time of each thyristor in series is inconsistent, the thyristor turned on later will bear a higher overvoltage, and in severe cases, the thyristor will be damaged, how to ensure that the turn-on time of each thyristor in series is consistent and can monitor the working state of each thyristor in real time is a problem to be solved. Utility model content

[0006] To solve the technical problems listed in the background art, the utility model provides a main network mobile type direct current ice melting device rectifier valve. The specific technical scheme is as follows:

[0007] The rectifier valve comprises a thyristor state detection module, a thyristor synchronous triggering module, a 12-pulse rectifier circuit electrically connected with the DC deicing device, and a thyristor control module in communication connection with the control and protection system of the DC deicing device; each single valve in the 12-pulse rectifier circuit is formed by connecting a plurality of thyristor protection units in series, each thyristor protection unit is formed by connecting a thyristor, a freewheeling diode, a static voltage-sharing resistor, and a dynamic voltage-sharing resistor-capacitor in parallel, and the current direction of the freewheeling diode is opposite to that of the thyristor; each thyristor protection unit is electrically connected with the thyristor state detection module, the thyristor state detection module is in communication connection with the thyristor control module, and the input end of the thyristor synchronous triggering module is used for receiving the control signal of the thyristor control module, and the output end is electrically connected with the gate of the thyristor in each thyristor protection unit.

[0008] Preferably, the number of thyristor stages in each single valve is the sum of the minimum number of thyristor stages of the rectifier valve and the redundancy number, wherein the minimum number of thyristor stages N min = U m × K R × K G × K D / V RMM , and the redundancy number N r ≥ (F r / 1-F r )× N min , wherein U m is the peak voltage on the valve side, K R is the voltage rise coefficient on the valve side, K G is the overvoltage coefficient, K D is the voltage distribution coefficient of the thyristor valve, V RMM is the reverse repetitive peak voltage of the thyristor, and F r is the redundancy.

[0009] Preferably, the rated current I T of the thyristor of the rectifier valve of the DC deicing device is I i ≥ k d × (2 / π)× (I i / √3), wherein k d is the current margin coefficient, and I J is the rated DC current of the DC deicing device.

[0010] Preferably, the resistance of the static voltage-sharing resistor is R RMM = 0.3× V L， / I RMM , wherein V L is the reverse repetitive peak voltage of the thyristor, and I 2 is the leakage current of the thyristor; the rated voltage of the static voltage-sharing resistor is greater than the rated voltage of the thyristor; and the rated power of the static voltage-sharing resistor is (U0 / N) J / RWherein U0 is the output voltage of the DC deicing device, N is the number of thyristors, R J is the resistance value of the static voltage-sharing resistor.

[0011] Preferably, the capacitance value of the capacitor in the dynamic voltage-sharing resistor-capacitor is C d = K x I TO x Δt on / V RMM， Wherein K is a coefficient, 1-3; I TO is the rated average on-state current; Δt on is the thyristor conduction time difference.

[0012] Preferably, the thyristor state detection module is used for real-time detection of thyristor voltage zero-crossing, current zero-crossing, backup protection and health status.

[0013] Preferably, the thyristor control module is used for receiving a trigger light signal issued by a DC deicing device control protection system, and converting the trigger light signal into an input signal of a thyristor synchronous trigger module.

[0014] Preferably, the thyristor synchronous trigger module includes an energy storage circuit, a trigger switch, a synchronous pulse transformer and a shaping protection circuit, and can synchronously trigger the conduction of the cascaded thyristors.

[0015] Preferably, the energy storage circuit of the thyristor synchronous trigger module includes a rectifier circuit and an energy storage element, and is used for providing power supply for generation of a low-voltage trigger pulse; the trigger switch is a silicon carbide power MOSFET, and is used for triggering the turn-on and turn-off of the trigger pulse; the synchronous pulse transformer adopts a single-primary multi-secondary multi-winding synchronous transformer, and realizes synchronous conduction of the cascaded thyristors in each valve of the rectifier valve; and the shaping protection circuit is used for current limiting, voltage dividing, shaping and reverse voltage protection of the pulse signal.

[0016] Preferably, the thyristor control module is used for receiving a state detection signal sent by the thyristor state detection module, judging the running state of the thyristor, and sending the running state to the DC deicing device control protection system, and receiving an instruction issued by the DC deicing device control protection system after research and judgment.

[0017] Compared with the prior art, the utility model has the following advantages:

[0018] By configuring static voltage-sharing resistor, dynamic voltage-sharing resistor-capacitor and freewheeling diode, the thyristor can realize the average distribution of the valve-side voltage in each working state such as forward blocking, reverse blocking and dynamic process of conduction and cutoff of the thyristor, and on the basis of static voltage-sharing protection and dynamic voltage-sharing protection of the series thyristor, the thyristor synchronous triggering module is added, the consistency of triggering and conduction of each series thyristor in the single valve is further improved, the voltage distribution uneven phenomenon caused by inconsistent thyristor conduction time is significantly reduced from the source, and through the configuration of the thyristor state detection module, the voltage zero-crossing, current zero-crossing, backup protection, device damage operation state are detected in real time, the fault information is found and uploaded in time, the system initiatively alarms or stops to protect, and the reliability of the core components of the rectifier valve and the whole DC deicing device is improved. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is a main net mobile DC deicing device rectifier valve structure schematic diagram in the embodiments of the utility model; DETAILED DESCRIPTION

[0020] In order to make the purpose, technical scheme and advantage of the utility model more clear, the utility model is described below in combination with drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments, all other embodiments obtained by the person skilled in the art without making creative labor belong to the protection scope of the utility model.

[0021] As Figure 1 Indicated, the utility model adopts the following technical scheme specifically: the rectifier valve adopts 12 pulse rectifier circuit, each single valve is composed of thyristor cascade, including series thyristor, freewheeling diode, static voltage-sharing resistor, dynamic voltage-sharing resistor-capacitor, thyristor state detection module, and the rectifier valve also includes thyristor control module and thyristor synchronous triggering module, realizes the synchronous control to each single valve thyristor.

[0022] The series of single valve thyristor of the DC deicing device rectifier valve is the sum of the minimum thyristor series and the redundant series of the rectifier valve, wherein the minimum thyristor series N min = U m × K R × K G × K D / V RMM , the redundant series N r ≥ (F r / 1-F r ) × N min , U m is the peak value of the valve-side voltage, K R is the valve-side voltage rise coefficient (1.07), K G is the overvoltage coefficient (2.2), KD is the voltage distribution coefficient of the thyristor valve (1.1), V RMM is the reverse repetitive peak voltage of the thyristor; F r is the redundancy, F r should not be less than 10%.

[0023] The rated current I of the rectifier valve thyristor of the DC deicing device T ≥ k i × (2 / π) × (I d / √3), wherein k i is the current margin coefficient, 3; I d is the rated DC current of the DC deicing device.

[0024] The freewheeling diode is connected in reverse parallel with each thyristor to ensure reliable turn-off of the thyristor, and the rated voltage of the diode is equal to the rated voltage of the thyristor.

[0025] The static voltage-sharing resistor is connected in parallel with each thyristor, and the resistance value of the static voltage-sharing resistor is R J = 0.3 × V RMM / I L , wherein V RMM is the reverse repetitive peak voltage of the thyristor, and I L is the leakage current of the thyristor; the rated voltage of the static voltage-sharing resistor is greater than the rated voltage of the thyristor; and the rated power of the static voltage-sharing resistor is (U0 / N) 2 / R J , wherein U0 is the output voltage of the DC deicing device, N is the number of thyristors, and R J is the resistance value of the static voltage-sharing resistor.

[0026] The dynamic voltage-sharing resistor-capacitor series is connected in parallel with each thyristor, and the capacitance value of the capacitor is C d = K × I TO × Δt on / V RMM , wherein K is a coefficient, 1-3; I TO is the rated average on-state current; Δt on is the thyristor turn-on time difference.

[0027] The rectifier valve of the DC deicing device has real-time detection functions of zero-crossing of the voltage and current of the thyristor, the zero-crossing of the voltage of the thyristor is detected through the process of the voltage across the thyristor changing from negative to positive, and the zero-crossing of the current of the thyristor is detected through the process of the voltage across the thyristor changing from positive to negative.

[0028] The rectifier valve of the DC deicing device has a real-time detection function of backup protection state of the thyristor, and the backup protection state of the thyristor is detected through a short-time overvoltage state.

[0029] The rectifier valve of the direct current ice melting device has a thyristor health state real-time detection function.

[0030] The rectifier valve of the direct current ice melting device has a thyristor voltage zero-crossing, current zero-crossing state real-time detection, backup protection state real-time detection, and health state real-time detection function, which is realized by a thyristor state detection module.

[0031] The thyristor state detection module sends a state detection signal to the thyristor control module after completing real-time state detection of the thyristor.

[0032] The thyristor control module receives a trigger light signal issued by a control protection system of the direct current ice melting device, converts the trigger light signal into an electrical signal, and uses the electrical signal as an input signal of a thyristor synchronous trigger module.

[0033] The thyristor synchronous trigger module includes an energy storage circuit, a trigger switch, a synchronous pulse transformer, and a shaping protection circuit, and finally synchronously triggers the series-connected thyristors.

[0034] The energy storage circuit of the thyristor synchronous trigger module includes a rectifier circuit and an energy storage element, and is used to provide power supply for generation of a low-voltage trigger pulse; the trigger switch is a silicon carbide power MOSFET, and is used to turn on and turn off the trigger pulse; the synchronous pulse transformer is a single-primary multi-secondary multi-winding synchronous transformer, and is used to realize synchronous conduction of the cascaded thyristors in each valve of the rectifier valve; and the shaping protection circuit is used for current limiting, voltage dividing, pulse shaping, and reverse voltage protection.

[0035] The thyristor control module receives the state detection signal sent by the thyristor state detection module, judges the running state of the thyristor, and sends the running state to a control protection system of the direct current ice melting device, so that the control protection system issues an alarm or a shutdown instruction according to a fault condition.

[0036] Finally, it should be noted that the above description is only a preferred embodiment of the utility model, and is not used to limit the utility model, although the utility model has been described in detail with reference to the foregoing embodiments, for those skilled in the art, the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced equivalently. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the utility model should be included in the protection scope of the utility model.

Claims

1. A rectifier valve of a mobile DC de-icing device of a main grid, characterized in that The thyristor state detection module, the thyristor synchronous trigger module, the 12-pulse rectifier circuit electrically connected with the DC deicing device, and the thyristor control module in communication connection with the DC deicing device control protection system are included.

2. The rectifier valve of the mobile DC de-icing device of the main network according to claim 1, characterized in that, The number of thyristors in each single valve is the sum of the minimum number of thyristors in the rectifier valve and the number of redundancy, wherein the minimum number of thyristors N min = U m × K R × K G × K D / V RMM , the number of redundancy N r ≥ (F r / 1-F r )× N min , wherein U m is the peak voltage on the valve side, K R is the voltage rise coefficient on the valve side, K G is the overvoltage coefficient, K D is the thyristor valve voltage distribution coefficient, V RMM is the reverse repetitive peak voltage of the thyristor; and F r is the redundancy.

3. The rectifier valve of claim 2, wherein, The rated current I of the thyristor of the rectifier valve of the DC de-icing device T ≥ k i × (2 / π) × (I d / √3), wherein k i is a current margin coefficient; I d is the rated DC current of the DC de-icing device.

4. The rectifier valve of claim 3, wherein The resistance of the static voltage-sharing resistor is R J = 0.3 x V RMM / I L , wherein V RMM is the reverse repetitive peak voltage of the thyristor, I L is the leakage current of the thyristor; the rated voltage of the static voltage-sharing resistor is greater than the rated voltage of the thyristor; the rated power of the static voltage-sharing resistor is (U0 / N) 2 / R J , wherein U0 is the output voltage of the DC de-icing device, N is the number of thyristors, and R J is the resistance of the static voltage-sharing resistor.

5. The rectifier valve of claim 4, wherein, The capacitance of the dynamic equalizing resistor-capacitor is C d = K x I TO x Δt on / V RMM Wherein K is a coefficient, 1-3; I TO is the rated average current; Δt on is the thyristor conduction time difference.

6. The rectifier valve of claim 5, wherein The thyristor state detection module is used for real-time detection of thyristor voltage zero-crossing, current zero-crossing, backup protection, and health status.

7. The rectifier valve of claim 6, wherein the rectifier valve is a main grid mobile DC de-icing device rectifier valve. The thyristor control module is used for receiving a trigger light signal issued by the DC deicing device control protection system and converting the trigger light signal into an input signal of the thyristor synchronous trigger module.

8. The rectifier valve of claim 7, wherein, The thyristor synchronous trigger module includes an energy storage circuit, a trigger switch, a synchronous pulse transformer, and a shaping protection circuit, and can synchronously trigger the conduction of the cascaded thyristors.

9. The rectifier valve of the mobile DC de-icing device of the main network according to claim 8, characterized in that, The energy storage circuit of the thyristor synchronous trigger module includes a rectifier circuit and an energy storage element, and is used for providing power supply for generation of a low-voltage trigger pulse; the trigger switch is a silicon carbide power MOSFET, and is used for turning on and turning off the trigger pulse; The synchronous pulse transformer is a single-primary multi-secondary multi-winding synchronous transformer, and realizes synchronous conduction of the cascaded thyristors in the rectifier valve single valve; and the shaping protection circuit is used for current limiting, voltage dividing, shaping, and reverse voltage protection of the pulse signal.

10. The rectifier valve of claim 9, wherein, The thyristor control module is used for receiving a state detection signal sent by the thyristor state detection module, judging the running state of the thyristor, and sending the running state to the DC deicing device control protection system, and receiving an instruction issued by the DC deicing device control protection system after research and judgment.

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