Boost capacity expansion circuit

Abstract

The utility model discloses a boost capacity expansion circuit comprising a self-coupling boost transformer T1, a power transformer B1 and a commutation bridge B2. The T1 is connected with the voltage output end of the voltage-stabilized power supply AC and is used for boosting the output voltage of the voltage-stabilized power supply AC and then outputting the output voltage to the B2; b2 which is connected with the self-coupling step-up transformer T1 and is used for controlling whether to provide voltage to the input end of the power transformer B1 after commutation after receiving the voltage output by the self-coupling step-up transformer T1; and B1 is respectively connected with the output end of the commutation bridge B2 and the output end of the voltage-stabilized power supply AC, and is used for reducing the voltage output by the commutation bridge B2, superposing the obtained voltage with the output voltage of the voltage-stabilized power supply AC, and outputting the superposed voltage to an external load to supply power to the load. According to the utility model, the output power of the voltage-stabilized power supply can be supplemented, and the power finally output to the load is increased, thereby realizing the purpose of capacity expansion of the voltage-stabilized power supply.

Description

Technical Field

[0001] The utility model relates to the technical field of circuit design, in particular to a voltage boosting and capacity expansion circuit. Background Art

[0002] Rail transit is an important form of transportation in my country. Railway signal power supply is one of the most important core components of rail transit signal system. Contactless voltage stabilizer is the core component of signal power supply. After the signal power supply is stabilized by contactless voltage stabilizer, it provides stable working voltage for subsequent lighting equipment, switch equipment and other equipment.

[0003] The contactless voltage regulator is developed based on the original brushless voltage regulator. The mechanical brushes are removed and the output voltage is compensated by transformers in stages. The output voltage is stable within the set range. At present, the power of the voltage regulator generally includes 3.5KVA, 5KVA and 10KVA capacities.

[0004] With the rapid development of railway transportation, the power of railway signal power supply is getting bigger and bigger, and the original power can no longer meet the needs of on-site use.

[0005] Therefore, there is an urgent need to develop a technology that can supplement the output power of a voltage-stabilized power supply (such as a contactless voltage-stabilized power supply) and increase the power ultimately output to the load, thereby achieving the purpose of expanding the capacity of the voltage-stabilized power supply. Utility Model Content

[0006] The utility model aims to provide a voltage boosting and capacity expansion circuit to solve the technical defects in the prior art.

[0007] To this end, the utility model provides a boost capacity expansion circuit, including: an auto-coupling boost transformer T1, a power transformer B1 and a commutation bridge B2;

[0008] The auto-coupling step-up transformer T1 is connected to the voltage output terminal of the external voltage-stabilized power source AC, and is used to step up the output voltage of the voltage-stabilized power source AC and then output it to the commutation bridge B2;

[0009] The commutation bridge B2 is connected to the auto-coupling step-up transformer T1 and is used to control whether to provide voltage to the input end of the power transformer B1 after commutation after receiving the voltage output by the auto-coupling step-up transformer T1 after the voltage is stepped up;

[0010] The power transformer B1 is connected to the output end of the commutation bridge B2 and the voltage-stabilized power supply AC, respectively, and is used to step down the voltage output by the commutation bridge B2, and then superimpose the obtained output voltage with the output voltage of the voltage-stabilized power supply AC, and then output it to an external load to power the load.

[0011] It can be seen from the technical solution provided by the above utility model that, compared with the prior art, the utility model provides a boost and capacity expansion circuit, which is scientifically designed and can supplement the output power of a regulated power supply (such as a contactless regulated power supply), increase the power ultimately output to the load, thereby achieving the purpose of expanding the capacity of the regulated power supply, and has great practical significance.

[0012] After testing, it is found that the circuit provided by the utility model can improve the output power of the voltage-stabilized power supply without changing the current voltage-stabilized power supply structure (the original structure of the existing voltage-stabilized power supply) and without replacing components. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 An electrical schematic diagram of a voltage-boosting and capacity-expanding circuit provided by the utility model;

[0014] Figure 2 An electrical schematic diagram of a voltage boosting and capacity expansion circuit provided by the utility model;

[0015] Figure 3 The utility model provides a specific connection electrical schematic diagram of a boost and capacity expansion circuit and a load. DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0017] In the description of this patent, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "set" should be understood in a broad sense, for example, it can be fixedly connected or set, or it can be detachably connected or set, or connected or set in one piece. For ordinary technicians in this field, the specific meanings of the above terms in this patent can be understood according to specific circumstances.

[0018] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0019] See also Figure 1The utility model provides a boosting and capacity expansion circuit, including: an auto-coupling boosting transformer T1, a power transformer B1 and a commutation bridge (i.e., a bridge commutation circuit) B2;

[0020] The auto-coupling step-up transformer T1 is connected to the voltage output terminal of the external voltage-stabilized power source AC, and is used to step up the output voltage (e.g., AC220V) of the voltage-stabilized power source AC (e.g., contactless voltage-stabilized power source) (e.g., step up to AC300V), and then output it to the commutation bridge B2;

[0021] The commutation bridge B2 is connected to the auto-coupling step-up transformer T1 and is used to control whether to provide voltage to the input end of the power transformer B1 after commutation after receiving the voltage output by the auto-coupling step-up transformer T1 after the voltage is stepped up;

[0022] The power transformer B1 is connected to the output end of the commutation bridge B2 and the voltage-stabilized power supply AC, respectively, and is used to step down the voltage output by the commutation bridge B2, and then superimpose the obtained output voltage (defined as the compensation voltage) with the output voltage of the voltage-stabilized power supply AC, and then output it to an external load to power the load.

[0023] It should be noted that the commutation bridge B2 can adjust and control whether the voltage output by the auto-coupling step-up transformer T1 is output to the input end of the power transformer B1 after phase switching, so that when the output voltage of the power transformer B1 is superimposed with the output voltage of the regulated power supply AC, the output voltage of the regulated power supply is added or subtracted accordingly based on whether they are in phase (in phase or in reverse phase). When the phase of the voltage output by the commutation bridge B2 to the power transformer B1 (that is, the provided voltage, that is, the input voltage of the power transformer B1) is in phase with the phase of the output voltage of the regulated power supply AC, the output voltage of the power transformer B1 is added to the output voltage of the regulated power supply AC, and when the phase of the voltage output by the commutation bridge B2 to the power transformer B1 is out of phase with the output voltage of the regulated power supply AC (specifically, in reverse phase), the output voltage of the power transformer B1 is subtracted from the output voltage of the regulated power supply AC.

[0024] It should also be noted that when the bidirectional thyristors K1 and K4 in the commutation bridge B2 are turned on at the same time, the phase of the voltage output by the commutation bridge B2 to the power transformer B1 (i.e. the voltage provided, i.e. the input voltage of the power transformer B1) is in phase with the phase of the output voltage of the regulated power supply AC;

[0025] When the bidirectional thyristors K2 and K3 of the commutation bridge B2 are turned on at the same time, the phase of the voltage output by the commutation bridge B2 to the power transformer B1 (that is, the provided voltage, that is, the input voltage of the power transformer B1) is opposite to the phase of the output voltage of the regulated power supply AC.

[0026] It should be noted that load refers to a device that receives electrical energy in a circuit, and is a general term for various electrical appliances. For example, common loads include resistors, light bulbs, air conditioners, motors and other power-consuming components. In the present utility model, load refers to lighting equipment, turnout equipment, etc. in the field of railway transportation.

[0027] In the present utility model, in specific implementation, the auto-coupling step-up transformer T1 is connected to an external voltage-stabilizing power supply, and the specific structural design is as follows:

[0028] The terminal e3 of the auto-coupling step-up transformer T1 is connected to the live wire terminal L of the voltage-stabilized power supply;

[0029] The terminal e1 of the auto-coupling step-up transformer T1 is connected to the neutral terminal N of the voltage-stabilized power supply;

[0030] Terminal e2 of the autotransformer T1 is connected to terminal a1 of the bidirectional thyristor K1 and terminal b1 of the bidirectional thyristor K2 in the commutation bridge B2 respectively.

[0031] The terminal e1 of the auto-coupling step-up transformer T1 is also connected to the terminal c2 of the bidirectional thyristor K3 and the terminal d2 of the bidirectional thyristor K4 in the commutation bridge B2 respectively.

[0032] It should be noted that, for the auto-coupling step-up transformer T1, terminal e1 serves as both an output terminal and an input terminal, terminal e3 is an input terminal, and terminal e2 is an output terminal.

[0033] It should be noted that the terminals e1 and e3 of the auto-coupling step-up transformer T1 are respectively connected to the "N" and "L" of the compensation input voltage (i.e., the regulated power supply AC). The step-up transformer here uses the auto-coupling mode, which can save half of the volume, and this link does not require coil isolation.

[0034] In the present utility model, in specific implementation, the commutation bridge B2 includes bidirectional thyristors K1 to K4;

[0035] In terms of specific implementation, regarding the internal connection of the commutation bridge B2 and the connection between the commutation bridge B2 and the subsequent power transformer B1, the specific structural design is as follows:

[0036] Terminal a1 of the bidirectional thyristor K1 is connected to terminal e2 of the auto-boosting transformer T1;

[0037] The terminal a2 of the bidirectional thyristor K1 is connected to the input terminal f2 of the power transformer B1 and the terminal c1 of the bidirectional thyristor K3 respectively;

[0038] The terminal b1 of the bidirectional thyristor K2 is connected to the terminal e2 of the auto-boosting transformer T1;

[0039] The terminal b2 of the bidirectional thyristor K2 is connected to the input terminal f1 of the power transformer B1 and the terminal d1 of the bidirectional thyristor K4 respectively;

[0040] Terminal c2 of the bidirectional thyristor K3 is connected to terminal e1 of the auto-boosting transformer T1;

[0041] See also Figure 3 As shown, the output terminal f3 of the power transformer B1 is respectively connected to the live wire terminal L of the regulated power source AC;

[0042] The output terminal f4 of the power transformer B1 is connected to the live wire end (i.e., the positive terminal) of the load;

[0043] The neutral terminal N of the voltage-stabilized power supply AC is connected to the neutral terminal (i.e., negative terminal) of the load;

[0044] It should be noted that based on Figure 3 As shown, the output voltage of the power transformer B1 is connected in series with the regulated power supply AC to form a series circuit, and then supply power to the load.

[0045] It should be noted that, for the present invention, if the power transformer B1 is to compensate the input voltage, it can be as follows: Figure 1 In the connection shown, depending on whether the commutation bridge B2 performs phase commutation on the voltage output by the auto-coupling step-up transformer T1, the input voltage and the compensation voltage can be added or subtracted accordingly. In specific implementation, by controlling the conduction sequence of the bidirectional thyristor "K1, K4" or "K2, K3", and considering that the stabilized power supply AC is connected in series with the output end of the power transformer B1, the output voltage provided by the stabilized power supply AC and the compensation voltage output by the power transformer B1 can be added or subtracted, and finally output to the positive terminal (live terminal) and the negative terminal (neutral terminal) of the external load.

[0046] It should be noted that K1~K4 are the core power control switch devices of the contactless voltage stabilizer, bidirectional thyristors (switching tubes for short), and their parameters are directly related to the performance of the system. At present, the rated voltage of the switching tube is 600V, the current is 40A, the rated voltage of the actual application is AC220V, and the maximum application current is 20A. According to the usual 1-fold selection principle, the rated working voltage of the switching tube can be increased to 300V, but the rated current has no room for improvement.

[0047] In the present utility model, in specific implementation, for Figure 3 In the improved boost circuit provided by the utility model shown, the power transformer B1 is designed to have a transformation ratio of 300:49.

[0048] See also Figure 2 , Figure 3As shown, when the bidirectional thyristors K1 and K4 in the commutation bridge B2 are turned on at the same time, the terminals f1 and f2 of the power transformer B1 introduce a phase (assuming it is positive, at this time the voltage input to the input end of the power transformer B1 is in phase with the voltage output by the autotransformer T1 after the voltage is stepped up), and an output voltage (i.e., compensation voltage) is generated at the output terminals f3 and f4 of the power transformer B1. Since the regulated power supply AC is connected in series with the output end of the power transformer B1 (because the output terminal f3 of the power transformer B1 is connected to the live wire terminal L of the regulated power supply AC), this voltage is superimposed on the output voltage provided by the regulated power supply AC, thereby realizing "positive" compensation for the output voltage of the regulated power supply AC (i.e., the voltage input to the circuit of the utility model);

[0049] Similarly, when the bidirectional thyristors K2 and K3 of the commutation bridge B2 are turned on, the power transformer B1 introduces an "anti-phase" (at this time, the voltage input to the input end of the power transformer B1 is in anti-phase with the voltage output by the autotransformer T1 after boosting), and an output voltage is generated at the output terminals f3 and f4 of the power transformer B1, which is connected in series with the output end of the regulated power supply AC and the power transformer B1 (because the output terminal f3 of the power transformer B1 is connected to the live wire terminal L of the regulated power supply AC). This voltage is superimposed on the output voltage provided by the regulated power supply AC, thereby realizing "anti-" compensation for the output voltage of the regulated power supply AC (i.e., the voltage input to the circuit of the present invention).

[0050] It should be noted that the method for controlling the on and off of the bidirectional thyristor in the commutation bridge B2 is a mature and well-known technology in the prior art and is a conventional application technology of bidirectional thyristor, which will not be described in detail here.

[0051] In the present utility model, in specific implementation, the circuit of the present utility model further includes: a protection fuse F1;

[0052] The protection fuse F1 is used to protect the bidirectional thyristors K1 to K4 from overcurrent;

[0053] In specific implementation, the terminal g1 of the protection fuse F1 is connected to the terminal a2 of the bidirectional thyristor K1 and the terminal c1 of the bidirectional thyristor K3 in the commutation bridge B2 respectively;

[0054] The terminal g2 of the protection fuse F1 is connected to the input terminal f2 of the power transformer B1.

[0055] It should be noted that the commutation bridge B2 is connected to the power transformer B1, and a fuse F1 is added in the middle to protect the bidirectional thyristors K1 to K4 (referred to as the switch tube). In actual operation, there will always be a random phenomenon of transformer primary saturation impact current, which may endanger the safety of the switch tube. Therefore, it is necessary to add a fast fuse F1 for protection.

[0056] In the utility model, the autotransformer T1 is an electrical device with mature prior art. In specific implementation, for the autotransformer T1, the contactless power supply is 10KVA, the transformation ratio of the autotransformer T1 is 220:300, the output power is 2.7KVA, and the output current is 9.8A.

[0057] In the utility model, the power transformer B1 is an electrical device with mature existing technology. In specific implementation, for the power transformer B1, the contactless power supply is 10KVA, the transformation ratio of the power transformer B1 is 300:49, the output power is 2.7KVA, and the output current is 55A.

[0058] In the present invention, the bidirectional thyristors K1 to K4 are electrical components with mature prior art, for example, the bidirectional thyristors of model BTA41-600B produced by STMicroelectronics (ST) can be used. In addition, currently domestically produced alternative products of the same model can also be used.

[0059] In the present invention, in a specific implementation, the protection fuse F1 is an electrical component with a mature prior art, and specifically can be a fuse with a specification of 600V / 15A.

[0060] In the present invention, based on the design of the present invention, the power can be upgraded and expanded without changing the current structure of the contactless voltage-stabilized power supply and without replacing the high-power switch tube in the voltage-stabilized power supply.

[0061] In the present utility model, it should be noted that the autotransformer step-up transformer T1 introduces the uncompensated voltage output by the voltage-stabilized power supply (such as a contactless voltage-stabilized power supply) into the transformer T1 for step-up. The step-up range of the transformer can be determined according to the system output power requirement and the withstand voltage value of the device. The boosted voltage is introduced into the commutation control bridge (i.e., the commutation bridge B2), and the commutation bridge B2 is used to drive the power transformer B1; the output voltage value of the power transformer B1 depends on the compensation output requirement.

[0062] After the step-up transformation, the output voltage of the power transformer B1 remains unchanged, but the primary voltage rating can be increased to AC300V according to the current parameters. According to the power P=U*I, when the maximum compensation current I remains unchanged, the coefficient of increase in voltage U is the coefficient of increase in power P.

[0063] It should also be noted that the autotransformer T1 is used to provide a higher input voltage for driving the power transformer B1. Under normal circumstances, the power transformer B1 is connected to a rated power frequency AC220V voltage. The current situation is that the current capacity of the bidirectional thyristor is only 40A, with no margin available, but the withstand voltage is 600V, which still has a large margin. According to P=U*I, when the compensation current is limited by the capacity of the switch tube and cannot be increased, increasing the compensation voltage U can effectively increase the compensation power. At present, the withstand voltage limit of the switch tube (i.e., bidirectional thyristor) is 600V. Taking half of the safety margin of 300V, when the compensation voltage is 300V, the power can be increased by 36% (because 300 / 220=1.36).

[0064] In summary, the utility model provides a reasonable and effective circuit that effectively expands the power of a contactless voltage-stabilized power supply without changing the current circuit structure of the existing voltage-stabilized power supply (i.e., the original structure of the existing voltage-stabilized power supply) and the device model on the voltage-stabilized power supply. It can expand the capacity of the current voltage-stabilized power supply module at low cost and provide an important reference for the flexible configuration of the existing power supply panel system (i.e., railway signal power supply).

[0065] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A boost and capacity expansion circuit, characterized in that: include: Auto-boosting transformer T1, power transformer B1 and commutation bridge B2; The auto-coupling step-up transformer T1 is connected to the voltage output terminal of the external voltage-stabilized power source AC, and is used to step up the output voltage of the voltage-stabilized power source AC and then output it to the commutation bridge B2; The commutation bridge B2 is connected to the auto-coupling step-up transformer T1 and is used to control whether to provide voltage to the input end of the power transformer B1 after commutation after receiving the voltage output by the auto-coupling step-up transformer T1 after the voltage is stepped up; The power transformer B1 is connected to the output end of the commutation bridge B2 and the voltage-stabilized power supply AC, respectively, and is used to step down the voltage output by the commutation bridge B2, and then superimpose the obtained output voltage with the output voltage of the voltage-stabilized power supply AC, and then output it to an external load to power the load.

2. The voltage boosting and capacity expansion circuit according to claim 1, characterized in that: The auto-coupling step-up transformer T1 is connected to an external voltage-stabilized power supply, and the specific structure design is as follows: The terminal e3 of the auto-coupling step-up transformer T1 is connected to the live wire terminal L of the voltage-stabilized power supply; The terminal e1 of the auto-coupling step-up transformer T1 is connected to the neutral terminal N of the voltage-stabilized power supply; The terminal e2 of the auto-coupling step-up transformer T1 is connected to the terminal a1 of the bidirectional thyristor K1 and the terminal b1 of the bidirectional thyristor K2 in the commutation bridge B2 respectively; The terminal e1 of the auto-coupling step-up transformer T1 is also connected to the terminal c2 of the bidirectional thyristor K3 and the terminal d2 of the bidirectional thyristor K4 in the commutation bridge B2 respectively.

3. The voltage boosting and capacity expanding circuit according to claim 1 or 2, characterized in that: The commutation bridge B2 includes bidirectional thyristors K1 to K4; The terminal a2 of the bidirectional thyristor K1 is connected to the input terminal f2 of the power transformer B1 and the terminal c1 of the bidirectional thyristor K3 respectively; The terminal b1 of the bidirectional thyristor K2 is connected to the terminal e2 of the auto-boosting transformer T1; The terminal b2 of the bidirectional thyristor K2 is connected to the input terminal f1 of the power transformer B1 and the terminal d1 of the bidirectional thyristor K4 respectively; Terminal c2 of the bidirectional thyristor K3 is connected to terminal e1 of the auto-boosting transformer T1; The output terminal f3 of the power transformer B1 is respectively connected to the live wire terminal L of the voltage-regulated power source AC; The output terminal f4 of the power transformer B1 is connected to the live wire terminal of the load; The neutral terminal N of the regulated power supply AC is connected to the neutral terminal of the load.

4. The voltage boosting and capacity expansion circuit according to claim 3, characterized in that: When the bidirectional thyristors K1 and K4 in the commutation bridge B2 are turned on at the same time, the phase of the voltage provided by the commutation bridge B2 to the power transformer B1 is in phase with the phase of the output voltage of the regulated power supply AC, and the output voltage of the power transformer B1 is added to the output voltage of the regulated power supply AC; When the bidirectional thyristors K2 and K3 of the commutation bridge B2 are turned on at the same time, the phase of the voltage provided by the commutation bridge B2 to the power transformer B1 is opposite to the phase of the output voltage of the regulated power supply AC, and the output voltage of the power transformer B1 is subtracted from the output voltage of the regulated power supply AC.

5. The voltage boosting and capacity expanding circuit according to claim 3, characterized in that: Also includes: Protective fuse F1; The protection fuse F1 is used to protect the bidirectional thyristors K1 to K4 from overcurrent.

6. The voltage boosting and capacity expanding circuit according to claim 5, characterized in that: The terminal g1 of the protection fuse F1 is connected to the terminal a2 of the bidirectional thyristor K1 and the terminal c1 of the bidirectional thyristor K3 in the commutation bridge B2 respectively; The terminal g2 of the protection fuse F1 is connected to the input terminal f2 of the power transformer B1.

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