Mobile compact power supply device for emergency power supply

Abstract

The invention discloses a mobile compact power supply device for emergency power supply. The device comprises a current transformer for protection, a current transformer for metering, a circuit breaker and a high-capacity electromagnetic voltage transformer, the current transformer for protection, the current transformer for metering and the circuit breaker are connected in series with the high-capacity electromagnetic voltage transformer; the circuit breaker and the current transformer for protection form a high-voltage protection control system to provide relay protection for the device; the high-capacity electromagnetic voltage transformer comprises a high-capacity electromagnetic voltage transformer host, a control cabinet and a compensation cabinet, and provides power compensation of a power winding and error compensation of a voltage measurement winding of the device under a fluctuating load. And the current transformer for metering is used for metering the electric energy of the device.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical equipment, and more specifically, to a mobile compact power supply device for emergency power supply. Background Art

[0002] At present, for emergency power restoration, the main solution of power grid companies is to use prefabricated mobile substations, install complete sets of equipment on semi-trailer trailers, and install the equipment incoming lines on high-voltage transmission lines, so as to provide emergency power restoration for users who need power.

[0003] At present, the main solution for emergency power supply restoration by power grid companies is to use prefabricated mobile substations, which combine existing lightning arresters, high-voltage switches, power transformers, medium-voltage switches, relay protection and measurement and control devices. The main wiring diagram of a 20MVA-66kV / 10.5kV mobile substation is as follows: Figure 1 shown.

[0004] The prior art realizes mobile power supply by installing combined equipment on a semi-trailer, such as a 10kV mobile substation. The mobile substation is actually a combination of substation equipment placed on a semi-trailer, and is not truly integrated.

[0005] There are mainly three problems:

[0006] (1) The voltage level of this equipment is between 66kV and 132kV, and the capacity is between 5-50MVA. It is large in size, complex in system, high in cost, and has high requirements for roads and operation scenarios. In addition, it generally converts high voltage into 10kV distribution power. The user side also needs to provide a pole-mounted transformer to supply power to 380V users.

[0007] (2) Since the capacity of the power supply required for emergency power supply restoration is highly uncertain, when the load capacity is small, the power supply voltage increases, and when the load capacity is large, the power supply voltage decreases, resulting in an unstable power supply voltage.

[0008] (3) When the power supply load fluctuates, the measurement winding error is greatly affected, and high measurement accuracy cannot be guaranteed, which affects the voltage measurement and electric energy metering.

[0009] Therefore, a technology is needed to provide a mobile compact power supply device for emergency power supply. Summary of the invention

[0010] The technical solution of the present invention provides a mobile compact power supply device for emergency power supply, so as to solve the problem of how to provide a mobile compact power supply device for emergency power supply which is small and easy to transport.

[0011] In order to solve the above problems, the present invention provides a mobile compact power supply device for emergency power supply, the device comprising: a protective current transformer, a metering current transformer, a circuit breaker, and a large-capacity electromagnetic voltage transformer; the protective current transformer, the metering current transformer and the circuit breaker are connected in series with the large-capacity electromagnetic voltage transformer;

[0012] The circuit breaker and the protective current transformer form a high-voltage protection control system to provide relay protection for the device;

[0013] The large-capacity electromagnetic voltage transformer comprises: a large-capacity electromagnetic voltage transformer host, a control cabinet and a compensation cabinet, which provide power compensation of the power winding of the device under fluctuating load and error compensation of the voltage measurement winding;

[0014] The metering current transformer is used to measure the electric energy of the device.

[0015] Preferably, the primary voltage of the large-capacity electromagnetic voltage transformer is 66kV and above, and the rated voltage of the power winding is 220V or 380V; the rated voltage of the voltage measurement winding of the large-capacity electromagnetic voltage transformer is 100 / √3V, and the primary terminal of the large-capacity electromagnetic voltage transformer is connected to the 110kV high-voltage transmission line through a high-voltage bushing.

[0016] Preferably, it includes: the high-voltage protection control system provides overcurrent protection for the large-capacity electromagnetic voltage transformer. When a short circuit fault occurs inside the box of the large-capacity electromagnetic voltage transformer, the primary winding and its lead wire to the ground, the protective current transformer connected in series with the large-capacity electromagnetic voltage transformer monitors that the current increases beyond a threshold value and sends a current signal to the high-voltage protection control system, and the high-voltage protection control system controls the circuit breaker to disconnect.

[0017] Preferably, it also includes: connecting the error-compensated voltage measurement winding and the secondary winding of the metering current transformer connected in series to the primary winding of the large-capacity electromagnetic voltage transformer to an electric energy metering system, and measuring the electric energy of the large-capacity electromagnetic voltage transformer through the electric energy metering system.

[0018] Preferably, the power compensation of the large-capacity electromagnetic voltage transformer includes: an auxiliary transformer and a switching device; the secondary winding of the auxiliary transformer is connected in series with the power winding of the large-capacity electromagnetic voltage transformer; the primary winding of the auxiliary transformer is powered by an additional winding, the additional winding is provided with a tap, and each tap is provided with a tap switch device; the middle of the primary winding of the auxiliary transformer is provided with an axial head grounded, and both sides of the primary winding are wound with a preset number of turns; the positive and negative tap tap compensation of the primary winding is realized by controlling the switch K6 and the switch K7; the switch device K8 is provided at both ends of the primary winding of the auxiliary transformer, and when the voltage at both ends of the power winding is less than 100V, each tap switch device, the control switch K6 and the control switch K7 are disconnected, and the switch device K8 is closed.

[0019] Preferably, the power winding output voltage is used as an input variable U0 of the switching device action program;

[0020] When the input variable U0 is between 213.4V and 226.6V, the switch does not operate;

[0021] When the input variable U0>226.6V, the control switch K7 is closed, and the control switch K7 sequentially operates from the last tap switch device to the first tap switch device, including: first closing the last tap switch device K5, judging whether the input variable U0 is within the range of 213.4V to 226.6V; if the input variable U0 is not within the range of 213.4V to 226.6V, then closing the previous tap switch device K4 of the last tap switch device K5, and disconnecting the last tap switch device K5; and so on, sequentially operating toward the first tap switch device K1, until the input variable U0 is within the range of 213.4V to 226.6V, the control switch K7 is closed, and the control switch K7 is closed.

[0022] If the input variable U0 is less than 213.4V, determine whether the input variable U0 is less than 100V. If the input variable U0 is less than 100V, the switch device K8 is closed, and the other switches are disconnected, and the process ends. If 100V is less than the input variable U0 and less than 213.4V, the switch K6 is controlled to be closed, and the operation starts from the last tap switch device K5 to the first tap switch device K1 in sequence. The operation sequence is to close the last tap switch device K5 first, and determine whether the input variable U0 is within the range of 213.4V to 226.6V. If not, close the previous tap switch device K4 of the last tap switch device K5, and disconnect the last tap switch device K5. Similarly, the operation starts from the first tap switch device K1 in sequence until the requirement is met, and the process ends.

[0023] Preferably, the error compensation of the large-capacity electromagnetic voltage transformer includes an electromagnetic voltage transformer VT that converts the 220V power winding into a 57.7V measurement voltage, a current transformer CT that is connected in series to the power supply winding, and a current transformer CT that is connected in series to the power supply winding. b1 And the current transformer CT connected in series in the auxiliary circuit b2 ;

[0024] The current transformer CT b1 And the current transformer CT b2 Used for power winding circuit current and auxiliary circuit current The current transformer CT b1 And the current transformer CT b2 Connect the load error compensation impedance Z in parallel b1 and auxiliary loop error compensation impedance Z b1 , so that the output voltage of the metering winding of the electric energy metering system The error does not change with load fluctuations.

[0025] Preferably, the high-voltage winding of the large-capacity electromagnetic voltage transformer host comprises two separately wound winding packages with the same number of turns and the same cross-sectional area, and the lead ends and tail ends of the conductors of the two winding packages are connected in parallel.

[0026] Preferably, the coil of the large-capacity electromagnetic voltage transformer host is sleeved on a single column of the iron core, and shielding side plates are respectively provided on both sides of the coil;

[0027] The intersection of the shielding side plate and the iron core is designed to be hollowed out, and the high magnetic field strength area set in the shielding side plate adopts a circular hole hollowing design.

[0028] Preferably, the control cabinet of the large-capacity electromagnetic voltage transformer includes an output voltage automatic control system for the power winding, and the output voltage automatic control system includes: an electric quantity collection module, a digital-to-analog conversion module, a programmable logic controller module, and a human-computer interaction module; the electric quantity collection module is used to detect the voltage of the power winding, and the detected voltage is processed by the digital-to-analog conversion module and input into the programmable logic controller module; when the power load changes and causes the supply voltage to drop, the switching action of the tap switch device, the control switch K6, the control switch K7, and the switch device K8 is controlled by the programmable logic controller module, so that the output voltage protection of the large-capacity electromagnetic voltage transformer is stable.

[0029] The technical solution of the present invention provides a mobile compact power supply device for emergency power supply, the device includes: a protective current transformer, a metering current transformer, a circuit breaker, and a large-capacity electromagnetic voltage transformer; the protective current transformer, the metering current transformer and the circuit breaker are connected in series with the large-capacity electromagnetic voltage transformer; the circuit breaker and the protective current transformer form a high-voltage protection control system to provide relay protection for the device; the large-capacity electromagnetic voltage transformer includes: a large-capacity electromagnetic voltage transformer host, a control cabinet and a compensation cabinet to provide power compensation for the power winding of the device under fluctuating load and error compensation for the voltage measurement winding; the metering current transformer is used to measure the electric energy of the device. The large-capacity electromagnetic voltage transformer in a mobile compact power supply device for emergency power supply proposed by the technical solution of the present invention has power compensation and error compensation functions, can provide a stable 220V / 380V power supply voltage and measurement voltage, and integrates low-power current transformers, circuit breakers and other equipment to form a small GIS device. The equipment size is greatly reduced and the output voltage of the equipment is stabilized. Compared with the mobile substation, the equipment is flexible and compact, making it easy to transport. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] A more complete understanding of exemplary embodiments of the present invention may be obtained by referring to the following drawings:

[0031] Figure 1 It is a main wiring diagram of a 20MVA-66kV / 10.5kV mobile substation according to an existing implementation method;

[0032] Figure 2 A schematic diagram of a 20MVA-66kV / 10.5kV mobile substation according to a preferred embodiment of the present invention;

[0033] Figure 3 A schematic diagram of the main wiring of a 110 kV mobile compact power supply with a combined electrical appliance according to a preferred embodiment of the present invention;

[0034] Figure 4 It is a main wiring diagram of a 110kV mobile compact power supply with only a circuit breaker according to a preferred embodiment of the present invention;

[0035] Figure 5 A schematic diagram of a 110kV HGIS combined electrical appliance according to a preferred embodiment of the present invention;

[0036] Figure 6 A schematic diagram of a compact power supply circuit according to a preferred embodiment of the present invention;

[0037] Figure 7 A schematic diagram of a compact power supply structure according to a preferred embodiment of the present invention; wherein: Figure 7 (a) is a front view; Figure 7 (b) is a side view; Figure 7 (c) is a top view;

[0038] Figure 8 It is an overall structural diagram of a single-phase mobile compact power supply according to a preferred embodiment of the present invention;

[0039] Fig. 9 It is a schematic diagram of the overall structural design of a three-phase mobile compact power supply according to a preferred embodiment of the present invention;

[0040] Fig.10 A schematic diagram of the power compensation principle of a large-capacity electromagnetic voltage transformer according to a preferred embodiment of the present invention;

[0041] Fig.11 A PLC measurement and control flow chart according to a preferred embodiment of the present invention;

[0042] Fig.12 A schematic diagram of the error compensation principle according to a preferred embodiment of the present invention;

[0043] Fig.13 A schematic diagram of a segmented winding of a high voltage winding according to a preferred embodiment of the present invention;

[0044] Fig.14 A schematic diagram of the structural arrangement of a shielding side plate of a large-capacity electromagnetic voltage transformer according to a preferred embodiment of the present invention;

[0045] Fig.15 A schematic diagram of magnetic field distribution of a shielding side plate according to a preferred embodiment of the present invention;

[0046] Fig.16 It is a schematic diagram of an improvement of a shielding side plate according to a preferred embodiment of the present invention;

[0047] Fig.17 This is a physical diagram of an improved shielding side plate according to a preferred embodiment of the present invention;

[0048] Fig.18 It is a structural diagram of a compensation cabinet according to a preferred embodiment of the present invention; wherein, Fig.18 (a) is a top view; Fig.18 (b) is a side view;

[0049] Fig.19 A schematic diagram of an automatic control system according to a preferred embodiment of the present invention;

[0050] Fig. 20 A schematic diagram showing the economic comparison of two power supply modes according to a preferred embodiment of the present invention;

[0051] Fig.21A schematic diagram of a typical 110 kV mobile substation according to a preferred embodiment of the present invention; Fig.21 (a) High voltage switchgear; Fig.21 (b) 110KV transformer car; Fig.21 (c) is a 10KV distribution vehicle. DETAILED DESCRIPTION

[0052] Now, exemplary embodiments of the present invention are described with reference to the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely and to fully convey the scope of the present invention to those skilled in the art. The terms used in the exemplary embodiments shown in the accompanying drawings are not intended to limit the present invention. In the accompanying drawings, the same units / elements are marked with the same reference numerals.

[0053] Unless otherwise specified, the terms (including technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it is understood that the terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0054] The present invention proposes a large-capacity electromagnetic voltage transformer with stable voltage output and measurement error, and its main wiring diagram is as follows: Figure 3 and Figure 4 shown.

[0055] Figure 3 It is to connect the large-capacity electromagnetic voltage transformer with the 110kV HGIS combined electrical appliance. Figure 4 The isolating switch is simplified, and only the circuit breaker and current transformer are combined with a large-capacity electromagnetic voltage transformer. Figure 3 It is suitable for long-term installation outdoors and long-term power supply to users. The advantage of this combined equipment is that it is equipped with an isolating switch and a grounding switch, which is convenient for regular maintenance of the circuit breaker, but the equipment cost and floor space will increase. Figure 5 The 110kV HGIS combined electrical appliance produced by a certain company can realize metering, measurement and protection functions by combining a large-capacity electromagnetic voltage transformer with the combined electrical appliance.

[0056] Figure 4 It is suitable for short-term power restoration and also has power metering, voltage measurement and protection functions, which greatly reduces the equipment cost and the footprint can be further reduced. It is a highly integrated all-in-one device.

[0057] The equipment mainly includes the following technical contents:

[0058] (1) Design principle of mobile compact power supply

[0059] The schematic diagram of the compact power supply design is as follows Figure 6 As shown, it adopts an integrated structure design with SF6 gas insulation and has the functions of electric energy metering, voltage measurement, relay protection and voltage supply with a fluctuation range of less than ±3%.

[0060] like Figure 6 As shown, the present invention provides a mobile compact power supply device for emergency power supply, the device comprising: a protective current transformer, a metering current transformer, a circuit breaker, and a large-capacity electromagnetic voltage transformer; the protective current transformer, the metering current transformer, and the circuit breaker are connected in series with the large-capacity electromagnetic voltage transformer;

[0061] The circuit breaker and protective current transformer form a high-voltage protection control system to provide relay protection for the device;

[0062] The large-capacity electromagnetic voltage transformer includes: a large-capacity electromagnetic voltage transformer host, a control cabinet and a compensation cabinet, which provide power compensation of the power winding under fluctuating load and error compensation of the voltage measurement winding;

[0063] Metering current transformers are used to measure the electrical energy of the device.

[0064] Its structural diagram is as follows Figure 7 As shown, the compact mobile power supply is mainly composed of a large-capacity electromagnetic voltage transformer host, a circuit breaker, a low-power current transformer, a protective current transformer (built-in), an outlet bushing, a control cabinet and a compensation cabinet. Among them: the large-capacity electromagnetic voltage transformer host, the control cabinet and the compensation cabinet constitute a large-capacity electromagnetic voltage transformer, which can realize power compensation of the power winding under fluctuating load and error compensation of the voltage measurement winding. The circuit breaker 1101 switch and the protective current transformer CT1 constitute a high-voltage protection system to realize the relay protection function of the equipment. The low-power current transformer CT2 and the voltage metering winding 1a1n realize the electric energy metering of the equipment.

[0065] The functions of each component in the present invention are introduced as follows:

[0066] 1) Large-capacity electromagnetic voltage transformer

[0067] The large-capacity electromagnetic voltage transformer consists of three parts: a large-capacity electromagnetic voltage transformer host, a compensation cabinet and a control cabinet. The primary voltage is 66kV and above, the rated voltage of the power winding is 220V or 380V, and it can also be designed according to user needs. The rated voltage of the voltage measurement winding (metering winding) is 100 / √3V, and the primary terminal is directly connected to the 110kV high-voltage transmission line through a high-voltage bushing.

[0068] 2) High voltage protection control system

[0069] The high-voltage protection control system is an overcurrent protection control system for large-capacity electromagnetic voltage transformers. When a short circuit occurs inside the large-capacity power supply integrated transformer box, the primary winding and its lead wire to the ground, the protection-level current transformer CT1 connected in series with the primary winding of the large-capacity electromagnetic voltage transformer detects a sharp increase in current and transmits the current signal to the high-voltage protection control system. The high-voltage protection control system controls the circuit breaker 1101 to disconnect and cut off the current loop.

[0070] 3) Electricity metering system

[0071] The electric energy metering system adopts the "high supply and high metering" solution, and connects the error-compensated voltage measurement terminal 1a1n and the secondary winding of the metering-grade low-power current transformer CT2 connected in series with the primary winding of the large-capacity electromagnetic voltage transformer to the electric energy metering system to realize the electric energy metering of the large-capacity electromagnetic voltage transformer.

[0072] The mobile compact power supply structure of the present invention is designed as follows Figure 8 As shown. The compact power supply with optimized structure is placed on the semi-trailer, the large-capacity electromagnetic voltage transformer and circuit breaker are arranged horizontally, and the control cabinet, compensation cabinet and JP cabinet are placed next to the large-capacity electromagnetic voltage transformer. The device can be directly connected to the 110kV high-voltage transmission line through the outlet bushing, and the high-voltage voltage of 110kV and above is converted into a 220V power supply voltage through the large-capacity electromagnetic voltage transformer, and the power is directly supplied to the user.

[0073] The control cabinet is used to adjust the power supply voltage, the compensation cabinet is used to compensate for the measurement winding error, the JP cabinet is used for electric energy metering and voltage and current measurement, and the circuit breaker is used for current quick-break protection.

[0074] The overall structure design of the three-phase mobile compact power supply is as follows Fig. 9 As shown. Connect the three-phase PT to the three-phase circuit breaker and connect it to the high-voltage transmission line through the three-phase outlet bushing.

[0075] Preferably, the primary voltage of the large-capacity electromagnetic voltage transformer is 66kV and above, and the rated voltage of the power winding is 220V or 380V; the rated voltage of the voltage measuring winding of the large-capacity electromagnetic voltage transformer is 100 / √3V, and the primary terminal of the large-capacity electromagnetic voltage transformer is connected to the 110kV high-voltage transmission line through a high-voltage bushing.

[0076] Preferably, it includes: a high-voltage protection control system provides overcurrent protection for a large-capacity electromagnetic voltage transformer. When a short circuit fault occurs inside the box of the large-capacity electromagnetic voltage transformer, the primary winding and its lead wire to the ground, the protective current transformer connected in series with the large-capacity electromagnetic voltage transformer detects that the current increases beyond a threshold value and sends a current signal to the high-voltage protection control system, and the high-voltage protection control system controls the circuit breaker to disconnect.

[0077] Preferably, it also includes: connecting the error-compensated voltage measurement winding and the secondary winding of the metering current transformer connected in series to the primary winding of the large-capacity electromagnetic voltage transformer to an electric energy metering system, and measuring the electric energy of the large-capacity electromagnetic voltage transformer through the electric energy metering system.

[0078] Preferably, the power compensation of the large-capacity electromagnetic voltage transformer includes: an auxiliary transformer and a switching device; the secondary winding of the auxiliary transformer is connected in series with the power winding of the large-capacity electromagnetic voltage transformer; the primary winding of the auxiliary transformer is powered by an additional winding, and the additional winding is provided with a tap, and each tap is provided with a tap switch device; the middle of the primary winding of the auxiliary transformer is provided with an axial head grounded, and both sides of the primary winding are wound with a preset number of turns; the positive and negative tap tap compensation of the primary winding is realized by controlling the switch K6 and the switch K7; the switch device K8 is provided at both ends of the primary winding of the auxiliary transformer, and when the voltage at both ends of the power winding is less than 100V, each tap switch device, the control switch K6 and the control switch K7 are disconnected, and the switch device K8 is closed.

[0079] (3) Power compensation design of large-capacity electromagnetic voltage transformer

[0080] The power compensation principle of the large-capacity electromagnetic voltage transformer provided by the present invention is as follows: Fig.10 As shown in the figure, AN is the primary winding terminal, an is the power winding terminal, 1a-1n are the voltage measurement winding terminals, T is a large-capacity electromagnetic voltage transformer, and T1 is an auxiliary transformer with an independent iron core. 1 is the primary voltage, U 2 is the power winding voltage, U 2E is the output voltage of the power supply winding, U 3 is the additional winding output voltage, U 4 is the primary voltage of the auxiliary transformer, U 5 is the secondary voltage of the auxiliary transformer. f2 Connecting in series with the power winding of a large-capacity voltage transformer is equivalent to superimposing an electric potential on its power winding, thereby compensating the voltage. 3 For the auxiliary transformer primary winding N f2Power supply, additional winding is set with tapping, each tapping is set with a switch device K1-K5 for voltage adjustment. The middle of the auxiliary transformer primary winding is set with shaft head grounding, and N is wound on both sides. f1 Turns. Positive and negative tap compensation is achieved by controlling K6 and K7. A switch device K8 is set at both ends of the primary winding of the auxiliary transformer. When the voltage across an is less than 100V, K1-K7 is disconnected and K8 is closed.

[0081] Preferably, the power winding output voltage is used as the input variable U0 of the switching device action program;

[0082] When the input variable U0 is between 213.4V and 226.6V, the switch does not operate;

[0083] When the input variable U0>226.6V, the control switch K7 is closed, and the operation is performed from the last tap switch device to the first tap switch device in sequence, including: first closing the last tap switch device K5, judging whether the input variable U0 is within the range of 213.4V to 226.6V; if the input variable U0 is not within the range of 213.4V to 226.6V, then closing the previous tap switch device K4 of the last tap switch device K5, and disconnecting the last tap switch device K5; and so on, sequentially operating toward the first tap switch device K1, until the input variable U0 is within the range of 213.4V to 226.6V, the operation ends;

[0084] If the input variable U0 is less than 213.4V, determine whether the input variable U0 is less than 100V. If the input variable U0 is less than 100V, the switch device K8 is closed, and the other switches are disconnected, and the process ends. If 100V is less than the input variable U0 and less than 213.4V, the switch K6 is controlled to be closed, and the operation starts from the last tap switch device K5 to the first tap switch device K1 in sequence. The operation sequence is to close the last tap switch device K5 first, and determine whether the input variable U0 is within the range of 213.4V to 226.6V. If not, close the previous tap switch device K4 of the last tap switch device K5, and disconnect the last tap switch device K5. Similarly, the operation starts from the first tap switch device K1 in sequence until the requirement is met, and the process ends.

[0085] The present invention adopts the following method to compensate the voltage. On the one hand, it reduces the working voltage of the switch, greatly reduces the insulation cost and equipment size. On the other hand, by appropriately increasing the additional winding voltage and increasing the auxiliary transformer ratio, the working current of the switch can be greatly reduced.

[0086] The switch action procedure is: PLC collects the power winding output voltage as the input variable U 0 , such as U 0Between 213.4V and 226.6V, the switch does not work; 0 >226.6V, K7 is closed, and K5 is activated to K1 in turn. The action sequence is to close K5 first to determine whether the requirement of 213.4V to 226.6V is met. If not, close K4, disconnect K5, and activate K1 in turn until the requirement is met. If U 0 <213.4V, judge U0 Is it <100V? If it is <100V, K8 is closed, and the other switches are disconnected, and the process ends. If 100V < U0 < 213.4V, K6 is closed, and K5 moves to K1 in sequence. The action sequence is to close K5 first, and determine whether the requirement of 213.4V to 226.6V is met. If not, close K4, disconnect K5, and move to K1 in sequence until the requirement is met, and the process ends. The program flow chart is as follows: Fig.11 shown.

[0087] 1) Sort by K1, K2, K3, K4, K5, K6, K7, K8;

[0088] 2) Collect input variable U 0 , i.e., power winding output;

[0089] 3) Determine U 0 Is it between 213.4V and 226.6V?

[0090] 4) Like U 0 Between 213.4V and 226.6V, the switch does not operate;

[0091] 5) Like U 0 >226.6V, K7 is closed, and K5 is activated to K1 in sequence. The action sequence is to close K5 first to determine whether the requirement of 213.4V to 226.6V is met. If not, close K4, disconnect K5, and activate K1 in sequence until the requirement is met.

[0092] 6) Like U 0 <213.4V, judge U 0 Is it <100V? If it is <100V, K8 is closed and the other switches are opened, and the process ends.

[0093] 7) If 100V<U 0 <213.4V, K6 is closed, and K5 is activated to K1 in sequence. The action sequence is to close K5 first to determine whether the requirement of 213.4V~226.6V is met. If not, close K4, disconnect K5, and activate K1 in sequence until the requirement is met.

[0094] Preferably, the error compensation of the large-capacity electromagnetic voltage transformer includes an electromagnetic voltage transformer VT that converts the 220V power winding into a 57.7V measurement voltage, a current transformer CT that is connected in series to the power supply winding, and a current transformer CT that is connected in series to the power supply winding. b1 And the current transformer CT connected in series in the auxiliary circuit b2 ;

[0095] Current Transformer CT b1 And current transformer CT b2 Used for power winding circuit current and auxiliary circuit current The current transformer CT b1 And current transformer CT b2 Connect the load error compensation impedance Z in parallel b1 and auxiliary loop error compensation impedance Z b1 , so that the output voltage of the metering winding of the electric energy metering system The error does not change with load fluctuations.

[0096] The principle of the error compensation design of the large-capacity electromagnetic voltage transformer provided by the present invention is as follows: Fig.12 As shown in the figure, Z1 is the power load, and Z2 is the voltage measurement winding load. The metering VT is a precision electromagnetic voltage transformer used to convert the 220kV power winding voltage into a 57.7V measurement voltage. b1 It is a high-precision current transformer connected in series with the power supply winding, with a transformation ratio of k1. b2 It is a high-precision current transformer connected in series in the auxiliary circuit, with a transformation ratio of k2. The measurement accuracy of the two current transformers is required to be 0.2s level. b1 and CT b2 Realize the power winding loop current and auxiliary circuit current At the same time, a load error compensation impedance Z is connected in parallel to the secondary output of the current transformer. b1 and auxiliary loop error compensation impedance Z b2 . Then the output voltage of 1a1n is for:

[0097]

[0098] In formula (1), is the voltage after no-load error compensation, Used to compensate for the power winding load error component, Used to compensate for the error component of the auxiliary loop.

[0099] Preferably, the high-voltage winding of the main unit of the large-capacity electromagnetic voltage transformer includes two separately wound winding packages with the same number of turns and the same cross-sectional area, and the head and tail ends of the conductors of the two winding packages are connected in parallel.

[0100] The large-capacity electromagnetic voltage transformer provided by the present invention is composed of a host, a control cabinet and a compensation cabinet. The structural design of each part is introduced as follows.

[0101] 1) Design of main engine winding structure

[0102] In order to realize the large-capacity power supply function, the transformer is usually designed with heat sinks, etc., while the voltage transformer is a device used for voltage measurement. When working normally, the heat generated by its core and winding is very small, and the heat dissipation design of the equipment is often ignored during design. When the power supply capacity of the voltage transformer increases, the current of its winding increases. At the same time, because the voltage transformer has a much larger transformation ratio than the transformer, the number of primary winding turns is more, which is more unfavorable for heat dissipation.

[0103] To this end, the present invention proposes to achieve heat dissipation by winding high-voltage coils in parallel in sections and leaving heat dissipation channels between the high-voltage coils. Fig.13 shown.

[0104] Fig.13 The medium and high voltage windings are wound separately using two winding packages with the same number of turns and the same cross-sectional area. The head and tail ends of the two winding packages are connected in parallel, leaving a certain heat dissipation channel in the middle.

[0105] Preferably, the coil of the main unit of the large-capacity electromagnetic voltage transformer is sleeved on a single column of the iron core, and shielding side plates are respectively provided on both sides of the coil;

[0106] The intersection of the shielding side plate and the iron core is designed to be hollow, and the high magnetic field strength area set in the shielding side plate adopts a circular hole hollow design.

[0107] The present invention designs the low-voltage shielding side plate of the host. The structure of the electromagnetic voltage transformer coil core is as follows Fig.14 As shown, the coil is sleeved on a single column of the iron core. In order to make the electric field around the coil and the iron core uniform, shielding side plates are provided on both sides of the coil.

[0108] The magnetic field distribution of the present invention is as follows Fig.15 shown.

[0109] Different from the voltage transformer whose winding current is less than 1mA, the AC current passing through the winding of a large-capacity electromagnetic voltage transformer will be greater than 1A, and a time-varying magnetic field will be generated in the middle of the coil. Part of the leakage magnetic field will not pass through the iron core but through the shielding side plate, generating eddy current losses on the shielding side plate, thereby causing the temperature of the shielding side plate to rise.

[0110] In order to solve the problem of temperature rise of the shielding side plate, the present invention improves the device structure. The idea of ​​the improvement is to hollow out the area with high leakage magnetic field intensity to reduce eddy current loss. The specific structure of the improvement is as follows: Fig.16 and Fig.17 As shown, the intersection of the shielding side plate and the iron core is hollowed out, and at the same time, the area of ​​the shielding side plate with relatively high leakage magnetic field intensity is hollowed out with a small circular hole.

[0111] The compensation cabinet structure of the present invention is designed to integrate the current transformer, voltage transformer and impedance used for power compensation and error compensation into the compensation cabinet. The structure diagram is shown in FIG. Fig.18 shown.

[0112] Fig.18 Among them, 1- VT for measurement, 2- auxiliary transformer, 3- auxiliary transformer output terminal, 4- VT output terminal for measurement, 5- CT output terminal for current measurement, 6- compensation reactor, 7- current transformer for error compensation, 8- base.

[0113] Preferably, the control cabinet of the large-capacity electromagnetic voltage transformer includes an output voltage automatic control system for the power winding, and the output voltage automatic control system includes: an electric quantity collection module, a digital-to-analog conversion module, a programmable logic controller module, and a human-computer interaction module; the electric quantity collection module is used to detect the voltage of the power winding, and the detected voltage is processed by the digital-to-analog conversion module and input into the programmable logic controller module; when the power load changes and causes the power supply voltage to drop, the switching action of the tap switch device, the control switch K6, the control switch K7, and the switch device K8 is controlled by the programmable logic controller module, so that the output voltage protection of the large-capacity electromagnetic voltage transformer is stable.

[0114] Control cabinet design

[0115] The large-capacity electromagnetic voltage transformer control cabinet is mainly composed of the power winding output voltage automatic control system, which specifically includes four parts: power acquisition module, digital-to-analog conversion module, programmable logic controller (PLC) module, and human-computer interaction module. The structural diagram is shown in Fig.19 As shown. The power collection module detects the voltage of the power winding and inputs it into the PLC for processing after digital-to-analog conversion. When the power load changes and the power supply voltage decreases, the PLC controls the switch to connect windings with different voltage ratios to keep the output voltage of the large-capacity electromagnetic voltage transformer stable.

[0116] Among them, the hardware basis of the power collection module is the voltage transformer and IV converter.

[0117] The economic efficiency of a mobile compact power supply device for emergency power supply provided by the present invention is illustrated below by way of example.

[0118] Taking the supply of 1MVA construction power to remote areas as an example, Option 1: The traditional power supply solution requires the construction of long-distance low-voltage distribution lines to supply power to users; Option 2: Use a mobile compact power supply to directly introduce power from nearby high-voltage transmission lines to supply power to users. The "minimum unit load annual cost method" is used for economic analysis. That is, the costs incurred in different periods are converted to present values. At the same time, considering the different economic service lives of different power supply facilities, the equal annual value method is used to convert the present value of the costs into annual costs within the service life. Under the condition of a certain power capacity, the economic comparison of different power supply plans is carried out.

[0119] From the above comparison, it can be seen that the minimum unit load annual cost of using a compact power supply can save more than 300,000 yuan / MVA / year.

[0120] The flexibility of a mobile compact power supply device for emergency power supply provided by the present invention is illustrated below by way of example.

[0121] Disaster rescue sites often have poor roads, requiring disaster relief equipment to be flexible, compact, and easy to transport. The mobile compact power supply proposed in this patent has a significantly reduced volume and weight at the same voltage level, making it easier to transport on mountain roads. Compared with mobile substations, it is more suitable for emergency rescue and disaster relief scenarios.

[0122] Fig.21 It is a 20MVA-110 / 35 / 10.5kV mobile substation. The whole system consists of 1#110kV switch car, 2#110kV transformer car and 3#10kV distribution car. It is large in size and has high requirements for the site required for power supply.

[0123] At the same voltage level, the key parameter comparison of mobile substation and compact mobile power supply is shown in Table 1.

[0124] Table 1 Parameter comparison

[0125]

[0126]

[0127] As can be seen from the table above, its mass is 76% lower than that of the mobile substation, the total length is reduced by 72%, and the number of units is reduced from three to one. Compared with the mobile substation, this compact power supply is more flexible.

[0128] The mobile compact power supply with power compensation and error compensation functions can convert high voltages of 66kV and above into 220V for power supply. The compact mobile power supply is mainly composed of a large-capacity electromagnetic voltage transformer host, a circuit breaker, a low-power current transformer, a protective current transformer (built-in), an outlet bushing, a control cabinet and a compensation cabinet. Among them: the large-capacity electromagnetic voltage transformer host, the control cabinet and the compensation cabinet constitute a large-capacity electromagnetic voltage transformer, which can realize power compensation of the power winding and error compensation of the voltage measurement winding under fluctuating load. The circuit breaker 1101 switch and the protective current transformer CT1 form a high-voltage protection system to realize the relay protection function of the equipment. The low-power current transformer CT2 and the voltage metering winding 1a1n realize the electric energy metering of the equipment.

[0129] 2) The large-capacity electromagnetic voltage transformer consists of a large-capacity electromagnetic voltage transformer host, a compensation cabinet and a control cabinet. The primary voltage is 66kV and above, the rated voltage of the power winding is 220V or 380V, and can also be designed according to user needs. The rated voltage of the voltage measurement winding (metering winding) is 100 / √3V, and the primary terminal is directly connected to the 110kV high-voltage transmission line through a high-voltage bushing. The host refers to the large-capacity electromagnetic voltage transformer itself. The compensation cabinet is mainly used to integrate the auxiliary transformer for power compensation, the current transformer for error compensation and the compensation impedance. The control cabinet has a built-in PLC control unit and contactor, which is mainly used for automatic adjustment of the power winding voltage.

[0130] 3) The high-voltage protection control system is an overcurrent protection control system for a large-capacity electromagnetic voltage transformer. When a short circuit occurs inside the large-capacity power supply integrated transformer box, the primary winding and its lead wire to the ground, the protection-level current transformer CT1 connected in series with the primary winding of the large-capacity electromagnetic voltage transformer detects a sharp increase in current and transmits the current signal to the high-voltage protection control system. The high-voltage protection control system controls the circuit breaker 1101 to disconnect and cut off the current loop.

[0131] 4) The electric energy metering system adopts the "high supply and high metering" solution, and connects the error-compensated voltage measurement terminal 1a1n and the secondary winding of the metering-grade low-power current transformer CT2 connected in series with the primary winding of the large-capacity electromagnetic voltage transformer to the electric energy metering system to realize the electric energy metering of the large-capacity electromagnetic voltage transformer.

[0132] 5) Power compensation of large-capacity electromagnetic voltage transformer is performed by auxiliary transformer T 1 The secondary winding N of the auxiliary transformer is realized together with the switch devices K1-K8. f2 Connected in series with the power winding of the large-capacity voltage transformer. 3 For the auxiliary transformer primary winding N f1Power supply, additional winding is set with tapping, each tapping is set with a switch device K1-K5 for voltage adjustment. The middle of the auxiliary transformer primary winding is set with shaft head grounding, and N is wound on both sides. f1 Turns. Positive and negative tap compensation is achieved by controlling K6 and K7. A switch device K8 is set at both ends of the primary winding of the auxiliary transformer. When the voltage across an is less than 100V, K1-K7 is disconnected and K8 is closed.

[0133] 6) The switching device action procedure is: PLC collects the power winding output voltage as the input variable U 0 , such as U 0 Between 213.4V and 226.6V, the switch does not work; 0 >226.6V, K7 is closed, and K5 is activated to K1 in turn. The action sequence is to close K5 first to determine whether the requirement of 213.4V to 226.6V is met. If not, close K4, disconnect K5, and activate K1 in turn until the requirement is met. If U 0 <213.4V, judge U 0 Is it <100V? If <100V, K8 is closed and the other switches are disconnected, and the process ends. If 100V<U0<213.4V, K6 is closed, and K5 moves to K1 in sequence. The action sequence is to close K5 first to determine whether the requirement of 213.4V~226.6V is met. If not, close K4, disconnect K5, and move to K1 in sequence until the requirement is met, and the process ends.

[0134] 7) Large capacity electromagnetic voltage transformer error compensation is done by measuring VT, CT b1 and CT b2 The metering VT is a precision electromagnetic voltage transformer used to convert the 220V power winding voltage into a 57.7V measurement voltage. b1 It is a high-precision current transformer connected in series with the power supply winding. b2 For high-precision current transformers connected in series in the auxiliary circuit, the measurement accuracy of the two current transformers is required to be 0.2s level. b1 and CT b2 Realize the power winding loop current and auxiliary circuit current At the same time, a load error compensation impedance Z is connected in parallel to the secondary output of the current transformer. b1 and auxiliary loop error compensation impedance Z b2 The output voltage of the metering winding is The error will not change with load fluctuations.

[0135] 8) The large-capacity electromagnetic voltage transformer is designed to consist of a large-capacity electromagnetic voltage transformer host, a control cabinet and a compensation cabinet.

[0136] 9) The main high-voltage winding of the large-capacity electromagnetic voltage transformer is wound separately with two winding packages with the same number of turns and the same cross-sectional area. The head and tail ends of the two winding packages are connected in parallel, leaving a certain heat dissipation channel in the middle.

[0137] 10) In order to solve the problem of temperature rise of the shielding side plate, the intersection of the shielding side plate and the iron core is hollowed out. At the same time, the area of ​​the shielding side plate with relatively high leakage magnetic field intensity is hollowed out with small circular holes.

[0138] 11) The current transformer, voltage transformer and impedance used for power compensation and error compensation are integrated and installed in the compensation cabinet.

[0139] 12) The control cabinet of large-capacity electromagnetic voltage transformer is mainly composed of the automatic control system of power winding output voltage, which specifically includes four parts: power acquisition module, digital-to-analog conversion module, programmable logic controller (PLC) module, and human-computer interaction module. The power acquisition module detects the voltage of the power winding, and after digital-to-analog conversion, it is input into the PLC for processing. When the power load changes and the power supply voltage decreases, the PLC controls the switch to connect windings with different voltage ratios to keep the output voltage of the large-capacity electromagnetic voltage transformer stable.

[0140] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes. The schemes in the embodiments of the present invention may be implemented in various computer languages, for example, object-oriented programming language Java and literal scripting language JavaScript, etc.

[0141] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0142] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0143] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0144] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0145] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

[0146] The invention has been described above with reference to a few embodiments. However, it is readily apparent to a person skilled in the art that other embodiments than the ones disclosed above are equally within the scope of the invention, as defined by the appended patent claims.

[0147] Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a / said / the [means, components, etc.]" are to be openly interpreted as at least one instance of the means, components, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not necessarily have to be performed in the exact order disclosed, unless explicitly stated otherwise.

Claims

1. A mobile compact power supply device for emergency power supply, the device comprising: Protective current transformers, metering current transformers, circuit breakers, and large-capacity electromagnetic voltage transformers; The protective current transformer, the metering current transformer and the circuit breaker are connected in series with the large-capacity electromagnetic voltage transformer; The circuit breaker and the protective current transformer form a high-voltage protection control system to provide relay protection for the device; The large-capacity electromagnetic voltage transformer comprises: a large-capacity electromagnetic voltage transformer host, a control cabinet and a compensation cabinet, which provide power compensation of the power winding of the device under fluctuating load and error compensation of the voltage measurement winding; The metering current transformer is used to measure the electric energy of the device.

2. According to the device according to claim 1, the primary voltage of the large-capacity electromagnetic voltage transformer is 66kV and above, and the rated voltage of the power winding is 220V or 380V; the rated voltage of the voltage measurement winding of the large-capacity electromagnetic voltage transformer is 100 / √3V, and the primary terminal of the large-capacity electromagnetic voltage transformer is connected to the 110kV high-voltage transmission line through a high-voltage bushing.

3. The device according to claim 1, comprising: The high-voltage protection control system provides overcurrent protection for the large-capacity electromagnetic voltage transformer. When a short circuit fault occurs inside the box of the large-capacity electromagnetic voltage transformer, the primary winding and its lead wire to the ground, the protective current transformer connected in series with the large-capacity electromagnetic voltage transformer detects that the current increases beyond a threshold value and sends a current signal to the high-voltage protection control system. The high-voltage protection control system controls the circuit breaker to disconnect.

4. The apparatus according to claim 1, further comprising: The error-compensated voltage measurement winding and the secondary winding of the metering current transformer connected in series to the primary winding of the large-capacity electromagnetic voltage transformer are connected to the electric energy metering system, and the electric energy of the large-capacity electromagnetic voltage transformer is measured by the electric energy metering system.

5. The device according to claim 1, wherein the power compensation of the large-capacity electromagnetic voltage transformer comprises: Auxiliary transformer and switch device; the secondary winding of the auxiliary transformer is connected in series with the power winding of the large-capacity electromagnetic voltage transformer; The primary winding of the auxiliary transformer is powered by an additional winding, and a tap is set for the additional winding, and each tap is provided with a tap switch device; an axial head is set to be grounded in the middle of the primary winding of the auxiliary transformer, and a preset number of turns are wound on both sides of the primary winding; the positive and negative tap compensation of the primary winding is realized by the control switch K6 and the control switch K7; a switch device K8 is set at both ends of the primary winding of the auxiliary transformer, and when the voltage at both ends of the power winding is less than 100V, each tap switch device, the control switch K6 and the control switch K7 are disconnected, and the switch device K8 is closed.

6. The device according to claim 5, wherein the power winding output voltage is used as an input variable U0 of the switching device action program; When the input variable U0 is between 213.4V and 226.6V, the switch does not operate; When the input variable U0>226.6V, the control switch K7 is closed, and the operation starts from the last tap switch device to the first tap start device in sequence, including: To close the last tap switch device K5 first, determine whether the input variable U0 is within the range of 213.4V to 226.6V; If the input variable U0 is not within the range of 213.4V to 226.6V, then close the previous tap switch device K4 of the last tap switch device K5, and open the last tap switch device K5; And so on, the first tap switch device K1 is operated in sequence until the input variable U0 meets the requirement of being within the range of 213.4V to 226.6V. If the input variable U0 is less than 213.4V, determine whether the input variable U0 is less than 100V. If the input variable U0 is less than 100V, the switch device K8 is closed, and the other switches are disconnected, and the process ends. If 100V is less than the input variable U0 and less than 213.4V, the switch K6 is controlled to be closed, and the operation starts from the last tap switch device K5 to the first tap switch device K1 in sequence. The operation sequence is to first close the last tap switch device K5, and determine whether the input variable U0 is within the range of 213.4V to 226.6V. If not, close the previous tap switch device K4 of the last tap switch device K5, and disconnect the last tap switch device K5. And so on, the first tap switch device K1 is actuated in sequence until the requirements are met and the process ends.

7. The device according to claim 1, wherein the error compensation of the large-capacity electromagnetic voltage transformer comprises an electromagnetic voltage transformer VT that converts the 220V power winding into a 57.7V measurement voltage, a current transformer CT that is connected in series to the power supply winding, and a current transformer CT that is connected in series to the power supply winding. b1 And the current transformer CT connected in series in the auxiliary circuit b2 ; The current transformer CT b1 And the current transformer CT b2 Used for power winding circuit current and auxiliary circuit current The current transformer CT b1 And the current transformer CT b2Connect the load error compensation impedance Z in parallel b1 and auxiliary loop error compensation impedance Z b1 , so that the output voltage of the metering winding of the electric energy metering system The error does not change with load fluctuations.

8. The device according to claim 1, wherein the high-voltage winding of the large-capacity electromagnetic voltage transformer host comprises two separately wound winding packages with the same number of turns and the same cross-sectional area, and the head ends and tail ends of the conductors of the two winding packages are connected in parallel.

9. The device according to claim 1, wherein the coil of the large-capacity electromagnetic voltage transformer host is sleeved on a single column of the iron core, and shielding side plates are respectively provided on both sides of the coil; The intersection of the shielding side plate and the iron core is designed to be hollowed out, and the high magnetic field strength area set in the shielding side plate adopts a circular hole hollowing design.

10. The device according to claim 5, wherein the control cabinet of the large-capacity electromagnetic voltage transformer comprises an output voltage automatic control system of the power winding, and the output voltage automatic control system comprises: Power collection module, digital-to-analog conversion module, programmable logic controller module, human-computer interaction module; The power collection module is used to detect the voltage of the power winding, and the detected voltage is processed by the digital-to-analog conversion module and then input into the programmable logic controller module; when the power load changes and causes the power supply voltage to drop, the switching action of the tap switch device, the control switch K6, the control switch K7 and the switch device K8 is controlled by the programmable logic controller module, so that the output voltage protection of the large-capacity electromagnetic voltage transformer is stable.

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