Capacitor configuration system of host power supply device and method for avoiding self-excitation voltage
By rationally configuring capacitors and contactors in the host power supply device, the problem of self-excitation between the host motor and the capacitor is solved, and the safe and stable operation and energy-saving effect of the host power supply device are achieved.
Patent Information
- Application Number
- CN202411925716.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-25
- Publication Date
- 2025-05-02
AI Technical Summary
The capacitor configuration of the existing host power supply device fails to effectively avoid the self-excitation between the host motor and the capacitor, resulting in the safe and stable operation of the host power supply device, capacitor and host slot box being threatened.
A capacitor configuration system for the host power supply device is adopted, including an inverter, an output inductor, a second capacitor group, a section cabinet, a short-connection contactor, a first capacitor group, a host motor, a third capacitor group and a compensation cabinet. By reasonably configuring the capacitor and contactor, it is ensured that when the host power supply device is shut down, the back electromotive force of the host motor can be eliminated in time to avoid the occurrence of self-excitation.
It effectively avoids the self-excitation between the host motor and the capacitor, ensures the safe and stable operation of the host power supply device, capacitor and host slot box, reduces the consumption of active power, and improves the safety of the host power supply device.
Smart Images
Figure CN119921623A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of isotope separation, and in particular relates to a capacitor configuration system for a host power supply device and a method for avoiding self-excitation voltage. Background Art
[0002] The existing capacitor configuration of the host power supply device is determined only by experience or reactive power calculation formula, without considering that after the host power supply device is shut down, a high self-excited voltage may be generated between the host motor and the capacitor, which may cause harm to the host, capacitor and host slot box.
[0003] The host motor uses a high-speed hysteresis motor. When the power supply of the hysteresis motor is interrupted, a high back electromotive force will be generated due to the inertia and high speed. The host is powered by a power supply device. Since the host motor has a particularly high requirement for the power supply quality, an LC filter must be installed at the output end of the host power supply device. L represents inductance and C represents capacitance. Capacitor C has both the function of filtering and the function of compensating reactive power. However, the introduction of the LC filter will bring a problem. Due to the existence of the LC filter, when the inverter of the host power supply device is blocked and the output power supply is interrupted (the output contactor is disconnected at the same time), it is equivalent to the capacitor being directly connected in parallel to the host motor port. At this time, the host motor will generate a high back electromotive force due to the inertia and high speed. If the back electromotive force cannot be eliminated in time, it will be directly added to the capacitor. If the capacitor is not configured properly, it will cause self-excitation between the host motor and the capacitor, that is, after the host motor is disconnected from the power supply, the terminal voltage and stator current of the host motor will not only not decrease, but will rise rapidly, and the host motor will operate in the generator state. The high voltage caused by self-excitation will seriously affect the safe and stable operation of the host power supply device. Summary of the invention
[0004] The technical problem solved by the present invention is to provide a capacitor configuration system for a host power supply device and a method for avoiding self-excitation voltage, which can avoid the self-excitation phenomenon between the host motor and the capacitor, and ensure the safety of the host power supply device, the capacitor and the host slot box.
[0005] The technical solution adopted by the present invention is:
[0006] A capacitor configuration system for a host power supply device comprises a host power supply device, a section cabinet, a compensation cabinet, and a host slot box. The host power supply device is connected to one end of the section cabinet, the other end of the section cabinet is connected to one end of the host slot box, and the other end of the host slot box is connected to the compensation cabinet.
[0007] The host power supply device includes an inverter, an output inductor, a second capacitor group and an output contactor. The inverter is connected to one end of the output inductor, the other end of the output inductor is connected to one end of the output contactor, and the second capacitor group is connected in parallel between the output inductor and the output contactor.
[0008] The section cabinet includes a short-circuit contactor and a first capacitor group, the compensation cabinet includes a third capacitor group, and the other end of the output contactor is respectively connected in parallel with the short-circuit contactor, the first capacitor group, the host motor and the third capacitor group.
[0009] When the inverter in the host power supply device is started, the output contactor is turned on to supply power to the host motor, and the first capacitor group, the second capacitor group and the third capacitor group simultaneously provide reactive current to the host motor.
[0010] When the inverter in the host power supply device stops, the output contactor is disconnected, the second capacitor group is disconnected from the host motor, and the short-circuit contactor is turned on to eliminate the back electromotive force of the host motor.
[0011] If the short-circuit contactor fails to connect, the total capacity configuration of the first capacitor group and the third capacitor group has taken into account the occurrence of self-excitation, and self-excitation will not occur between the host motor and the first capacitor group and the third capacitor group.
[0012] The second capacitor group is disconnected as the output contactor is disconnected, and the third capacitor group is configured at the end of the host motor to reduce the current at the front end.
[0013] A method for avoiding self-excited voltage comprises the following steps:
[0014] S1. Determine the total reactive power required by the host motor, and determine the required total reactive power according to the inherent power factor, active power and target power factor of the host motor under rated working conditions;
[0015] S2. Determine the total capacity required by the main engine motor, and determine the total capacity required according to the frequency, voltage and total reactive power required of the main engine motor under rated working conditions;
[0016] S3, determining the current of the main engine motor during normal operation, and determining the current during normal operation according to the total active power, power factor and voltage of the main engine motor under rated working conditions;
[0017] S4, determining the maximum capacitance configured together with the host motor when self-excitation occurs, and determining the maximum capacitance configured together with the host motor according to the critical condition for self-excitation;
[0018] S5. Capacity configuration is performed for the capacitors configured together with the host motor. According to the capacity of the actual model, the total capacity is decomposed and configured on each phase;
[0019] S6. Position the capacitors configured with the host motor, and divide the capacitors configured with the host motor into two parts, one part is configured at the section cabinet at the head end of the host motor, and the other part is configured at the compensation cabinet at the end of the host motor;
[0020] S7, determining the capacitance not connected to the host motor, subtracting the capacitance configured with the host motor from the total capacitance, to obtain the capacitance not connected to the host motor, which is disconnected from the host motor when the host power supply device is shut down;
[0021] S8. Configure the capacity of the capacitors that are not connected to the main motor. According to the capacity of the actual model, decompose the total capacity and configure it on each phase;
[0022] S9. Position the capacitor that is not connected to the host motor and place it between the output inductor and the output contactor.
[0023] Compared with the prior art, the present invention has the following beneficial effects:
[0024] (1) The present invention provides a capacitor configuration system for a host power supply device and a method for avoiding self-excitation voltage, which can avoid self-excitation between the host motor and the capacitor, thereby ensuring the safety of the host, the capacitor and the host slot box. When the power supply device is shut down, the host will not be damaged by a rapid drop in frequency due to excessive self-excitation voltage, and the capacitor and the host slot box will not be damaged by insulation breakdown due to excessive self-excitation voltage.
[0025] (2) The present invention provides a capacitor configuration system for a host power supply device and a method for avoiding self-excitation voltage. The capacitors connected to the host motor are dispersedly configured at the head end and the tail end of the host motor. On the one hand, the active power consumed in the host slot box and the line is significantly reduced, and the energy-saving effect is significantly improved compared with the previous centralized compensation of the section cabinet. On the other hand, the current in the host slot box and the line is significantly reduced, which can improve the safety of the host power supply device.
[0026] (3) The present invention provides a capacitor configuration system for a host power supply device and a method for avoiding self-excitation voltage, and the actual power factor obtained is consistent with the expected result. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Figure 1 A schematic diagram of the structure of a capacitor configuration system for a host power supply device provided by the present invention;
[0028] Figure 2 A flow chart of a method for avoiding self-excitation voltage provided by the present invention;
[0029] In the figure: 1. host power supply device; 2. inverter; 3. output inductor; 4. output contactor; 5. section cabinet; 6. short-circuit contactor; 7. first capacitor group; 8. host motor; 9. second capacitor group; 10. third capacitor group; 11. compensation cabinet; 12. host slot box. DETAILED DESCRIPTION
[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0031] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.
[0032] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0033] like Figure 1 As shown, a capacitor configuration system for a host power supply device provided by the present invention comprises a host power supply device 1, a section cabinet 5, a compensation cabinet 11, and a host slot box 12, wherein the host power supply device 1 is connected to one end of the section cabinet 5, the other end of the section cabinet 5 is connected to one end of the host slot box 12, and the other end of the host slot box 12 is connected to the compensation cabinet 11;
[0034] The host power supply device 1 includes an inverter 2, an output inductor 3, a second capacitor group 9 and an output contactor 4. The inverter 2 is connected to one end of the output inductor 3, and the other end of the output inductor 3 is connected to one end of the output contactor 4. The second capacitor group 9 is connected in parallel between the output inductor 3 and the output contactor 4; the section cabinet 5 includes a short-circuit contactor 6 and a first capacitor group 7, and the compensation cabinet 11 includes a third capacitor group 10. The other end of the output contactor 4 is respectively connected in parallel with the short-circuit contactor 6, the first capacitor group 7, the host motor 8 and the third capacitor group 10.
[0035] When the inverter 2 in the host power supply device 1 is started, the output contactor 4 is connected to supply power to the host motor 8, and the first capacitor group 7, the second capacitor group 9 and the third capacitor group 10 simultaneously provide reactive current to the host motor 8. When the inverter 2 in the host power supply device 1 stops, the output contactor 4 is disconnected (when it is disconnected, the second capacitor group 9 is also disconnected from the host motor), and the short-circuit contactor 6 is connected to eliminate the back electromotive force of the host motor. If the short-circuit contactor 6 fails to connect or the operator cannot connect it in time due to incorrect operation, at this time, since the total capacity configuration of the first capacitor group 7 and the third capacitor group 10 has taken into account the self-excitation situation that occurs, self-excitation will not occur between the host motor 8 and the first capacitor group 7 and the third capacitor group 10. The second capacitor group 9 is disconnected as the output contactor 4 is disconnected. The third capacitor group 10 is configured at the very end of the host motor 8 to reduce the current at the front end and reduce losses.
[0036] like Figure 2 As shown, a method for avoiding self-excitation voltage provided by the present invention comprises the following steps:
[0037] S1. Determine the total reactive power required by the host motor, and determine the required total reactive power according to the inherent power factor, active power and target power factor of the host motor under rated working conditions.
[0038] S2. Determine the total capacitance required by the main engine motor, and determine the total capacitance required according to the frequency, voltage and total reactive power required of the main engine motor under rated working conditions.
[0039] S3. Determine the current of the main engine motor during normal operation, and determine the current during normal operation based on the total active power, power factor and voltage of the main engine motor under rated working conditions.
[0040] S4. Determine the maximum capacitance configured together with the host motor when self-excitation occurs, and determine the maximum capacitance configured together with the host motor based on the critical condition for self-excitation (the capacitor current configured together with the host motor is equal to the current when the host motor is operating normally).
[0041] S5. Configure the capacity of the capacitors configured together with the host motor. According to the capacity of the actual model, decompose the total capacity and configure it on each phase.
[0042] S6. Position the capacitors configured with the host motor. Considering that the host motor is a cluster and there are many cables between the motors, in order to reduce the loss of these cables and save energy, the capacitors configured with the host motor are divided into two parts, one part is configured in the section cabinet at the head end of the host motor, and the other part is configured in the compensation cabinet at the end of the host motor.
[0043] S7, determine the capacitance not connected to the host motor, subtract the capacitance configured with the host motor from the total capacitance, and obtain the capacitance not connected to the host motor. This portion of capacitance is disconnected from the host motor when the host power supply device is shut down.
[0044] S8. Configure the capacity of the capacitors that are not connected to the main motor. According to the capacity of the actual model, decompose the total capacity and configure it on each phase.
[0045] S9. Position the capacitor that is not connected to the host motor and place it between the output inductor and the output contactor.
[0046] This method can not only ensure that the host obtains more reasonable reactive power compensation during normal operation, but also ensure that no self-excitation occurs between the host motor and the capacitor when the host power supply device is shut down.
[0047] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.
[0048] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.
Claims
1. A capacitor configuration system for a host power supply device, characterized in that: The invention comprises a host power supply device (1), a section cabinet (5), a compensation cabinet (11), and a host slot box (12); the host power supply device (1) is connected to one end of the section cabinet (5), the other end of the section cabinet (5) is connected to one end of the host slot box (12), and the other end of the host slot box (12) is connected to the compensation cabinet (11).
2. The host power supply device capacitor configuration system according to claim 1, characterized in that: The host power supply device (1) comprises an inverter (2), an output inductor (3), a second capacitor group (9) and an output contactor (4); the inverter (2) is connected to one end of the output inductor (3), the other end of the output inductor (3) is connected to one end of the output contactor (4), and the second capacitor group (9) is connected in parallel between the output inductor (3) and the output contactor (4).
3. The host power supply device capacitor configuration system according to claim 2, characterized in that: The section cabinet (5) comprises a shorting contactor (6) and a first capacitor group (7), the compensation cabinet (11) comprises a third capacitor group (10), and the other end of the output contactor (4) is respectively connected in parallel to the shorting contactor (6), the first capacitor group (7), the main engine motor (8) and the third capacitor group (10).
4. The host power supply device capacitor configuration system according to claim 3, characterized in that: When the inverter (2) in the host power supply device (1) is started, the output contactor (4) is connected to supply power to the host motor (8), and the first capacitor group (7), the second capacitor group (9) and the third capacitor group (10) simultaneously provide reactive current to the host motor (8).
5. The host power supply device capacitor configuration system according to claim 4, characterized in that: When the inverter (2) in the host power supply device (1) stops, the output contactor (4) is disconnected, the second capacitor group (9) is disconnected from the host motor, and the short-circuit contactor (6) is connected to eliminate the back electromotive force of the host motor.
6. The host power supply device capacitor configuration system according to claim 5, characterized in that: If the short-circuit contactor (6) fails and cannot be connected, the total capacity configuration of the first capacitor group (7) and the third capacitor group (10) has taken into account the occurrence of self-excitation, and self-excitation will not occur between the main engine motor (8) and the first capacitor group (7) and the third capacitor group (10).
7. The host power supply device capacitor configuration system according to claim 6, characterized in that: The second capacitor group (9) is disconnected when the output contactor (4) is disconnected, and the third capacitor group (10) is configured at the end of the main engine motor (8) to reduce the current at the front end.
8. A method for avoiding self-excited voltage, characterized in that: The steps include: S1. Determine the total reactive power required by the host motor, and determine the required total reactive power according to the inherent power factor, active power and target power factor of the host motor under rated working conditions; S2. Determine the total capacity required by the main engine motor, and determine the total capacity required according to the frequency, voltage and total reactive power required of the main engine motor under rated working conditions; S3, determining the current of the main engine motor during normal operation, and determining the current during normal operation according to the total active power, power factor and voltage of the main engine motor under rated working conditions; S4, determining the maximum capacitance configured together with the host motor when self-excitation occurs, and determining the maximum capacitance configured together with the host motor according to the critical condition for self-excitation; S5. Capacity configuration is performed for the capacitors configured together with the host motor. According to the capacity of the actual model, the total capacity is decomposed and configured on each phase; S6. Position the capacitors configured with the host motor, and divide the capacitors configured with the host motor into two parts, one part is configured at the section cabinet at the head end of the host motor, and the other part is configured at the compensation cabinet at the end of the host motor; S7, determining the capacitance not connected to the host motor, subtracting the capacitance configured with the host motor from the total capacitance, to obtain the capacitance not connected to the host motor, which is disconnected from the host motor when the host power supply device is shut down; S8. Configure the capacity of the capacitors that are not connected to the main motor. According to the capacity of the actual model, decompose the total capacity and configure it on each phase; S9. Position the capacitor that is not connected to the host motor and place it between the output inductor and the output contactor.