CN209805486U - High-voltage pulse capacitor charging device - Google Patents

Abstract

A high-voltage pulse capacitor charging device comprises a battery and charging unit, a rectification power supply and a connecting switch, wherein the battery and charging unit comprises an energy storage inductor, n batteries and a charging module which are sequentially connected in series, and two ends of the series structure are connected with the output voltage of the rectification power supply; the battery and charging module comprises a battery module and a bidirectional DC/DC module which are connected in parallel, and the bidirectional DC/DC module in the n batteries and charging modules and the energy storage inductor form a cascade bidirectional DC/DC; the voltage at two ends of the battery and the charging unit is applied to the pulse capacitor through the connecting switch, when the connecting switch is disconnected, the battery module is charged by the cascade bidirectional DC/DC control rectification power supply, and when the connecting switch is closed, the battery module is charged to the pulse capacitor by the cascade bidirectional DC/DC control rectification power supply. The utility model discloses accomplish battery charging device and pulse capacitor charging device by same set of circuit, adopt cascade structure to improve equivalent switching frequency simultaneously, have the effect of high efficiency, low volume.

Description

A high-voltage pulse capacitor charging device

technical field

The utility model belongs to the field of power electronic devices. Places such as electromagnetic ejection require high-voltage pulse power, and the pulse power is usually obtained by discharging a high-voltage pulse capacitor. The utility model relates to a high-voltage pulse capacitor charging device, which can supply high-voltage pulse The charging capacity can be charged multiple times.

Background technique

Electromagnetic propulsion devices such as electromagnetic guns have attracted much attention because of their advantages such as low cost, long range, and good stability. When the electromagnetic propulsion device is working, it needs to emit tens to hundreds of megajoules of energy in a short period of time, thereby generating a huge driving force and pushing the projectile out at high speed. In order to reduce the capacity of the external power supply, a three-level power supply structure of power supply + energy storage system + pulse charging capacitor is usually adopted.

The primary power supply is usually an alternating current or direct current generated by an external power grid or a generator car, which supplies power to the secondary power supply with a small power before the propulsion device works, and stores the energy; the secondary power supply is usually composed of batteries, superconductors or flywheels The power supply system with energy storage function composed of the propulsion device will charge the three-stage energy storage pulse capacitor with high voltage and high power in a short time before the propulsion device works, so as to prepare for the thruster drive. The tertiary power supply is provided by a pulse capacitor, which releases megajoules of energy to the launch device in a very short time, thereby generating a huge thrust.

In order to ensure that the propulsion device has the ability to launch multiple times in a short time, the second-level power storage system usually only takes a few seconds to charge the third-level energy storage pulse capacitor once, and the charging power reaches several MW; at the same time, the second-level energy storage system stores The energy must meet the requirements of multiple launches of the propulsion system, and the total energy stored in the secondary energy storage system is several times that of the pulse capacitor.

The rated voltage of the pulse capacitor that supplies power to the propulsion system is usually several thousand volts. Therefore, the energy storage system and its charging and discharging device are high-voltage and high-power devices. Because of the high voltage, the energy storage battery of the energy storage system must be connected in series with multiple battery modules, and the energy storage battery system and the pulse capacitor are connected by a high-voltage, high-power charging device.

What Fig. 1 shows is the structural diagram of the existing pulse capacitor charging device. When charging the pulse capacitor, open in series and close K11-Kn1, 1# battery module-n# battery modules are connected in series to form a high-voltage DC voltage of several thousand volts, and the battery charges the pulse capacitor through the capacitor charging device.

Before charging the pulse capacitor, the battery must be charged first so that the battery is fully charged. In order to reduce the voltage level of the battery charging device, the battery is usually charged by charging each battery module separately. The structure of the charging device is shown in Figure 2 . In Fig. 2, 1# battery module-n# battery modules are respectively connected to the battery charging device through switches K11, K12-K1n, K2n, and the charging process is completed in sequence. After the battery charging is completed, the 1# battery module-n# battery modules are switched to the series structure shown in Figure 1 by switching the switch to prepare for the pulse capacitor charging. There are following problems in this scheme:

First, the circuit when charging the energy storage battery and the circuit when charging the pulse capacitor are two different circuits. The two circuits need to be switched by multiple switches to complete the switching of the working conditions, and the switching time is relatively long (it is understood that it takes 30 minutes. about);

Second, the battery charging device and the pulse capacitor charging device are two independent systems, which increase the volume, weight and cost of the system, which is not conducive to the miniaturization of the system.

Utility model content

Aiming at the above-mentioned traditional pulse capacitor charging device's complex switch switching and the shortcomings of two independent systems for battery charging and discharging, the utility model proposes a high-voltage pulse capacitor charging device that uses battery energy storage as a secondary energy storage power supply The charging of the pulse capacitor by the system, battery charging and pulse capacitor charging are completed by the same set of circuits, and the switching between the two working states of battery charging and pulse capacitor charging can be realized only by changing the control mode, without complicated switch conversion. The charging device proposed by the utility model saves system maintenance time and improves efficiency; reduces the weight and volume of the system and improves the mobility of the system.

The technical scheme of the utility model is:

A high-voltage pulse capacitor charging device, including a battery and a charging unit, a rectifying power supply and a connection switch,

The battery and the charging unit include energy storage inductors and n batteries and charging modules connected in series in sequence, and the two ends of the series structure are connected to the output voltage of the rectified power supply, wherein n is a positive integer; the battery and the charging module include parallel connected A battery module and a bidirectional DC/DC module, the bidirectional DC/DC modules in the n batteries and the charging module and the energy storage inductor form a cascaded bidirectional DC/DC;

The voltage at both ends of the battery and the charging unit is controlled by the connection switch and applied to both ends of the pulse capacitor. When the connection switch is disconnected, the cascaded bidirectional DC/DC controls the rectifier power supply to n The battery modules in the battery and charging module are charged, and when the connection switch is closed, the cascaded bidirectional DC/DC controls n battery modules in the battery and charging module to charge the pulse capacitor.

Specifically, the bidirectional DC/DC module in the i-th battery and charging module includes a DC side support capacitor, a first power switching device, a second power switching device, and a first diode antiparallel to the first power switching device and the second diode in anti-parallel connection with the second power switching device, one end of the first power switching device is connected to one end of the DC side support capacitor and one end of the i-th battery and the battery module in the charging module, and the other end is connected to One end of the second power switching device; the other end of the second power switching device is connected to the other end of the DC side support capacitor and the other end of the i-th battery and the battery module in the charging module; the two ends of the second power switching device are respectively Connect the output end of the i-1th battery and charging module and the input end of the i+1th battery and charging module as the input end and input end of the i-th battery and charging module, i∈[ 2, n-1]; the input end of the first battery and charging module is connected to one end of the rectifying power supply after passing through the energy storage inductor, and the output end of the nth battery and charging module is connected to one end of the rectifying power supply another side.

Specifically, the rectified power supply includes a circuit breaker, a main contactor, a transformer and four three-phase rectifiers, one end of the circuit breaker is connected to an external AC power supply, and the other end is connected to the primary winding of the transformer after passing through the main contactor; the secondary of the transformer includes Four three-phase windings with a phase angle difference of 15° in sequence, and the four three-phase windings are respectively output in series with voltages rectified by four three-phase rectifiers as the output voltage of the rectified power supply.

Specifically, the rectified power supply further includes an auxiliary contactor and a series surge suppression resistor, and the auxiliary contactor and the series surge suppression resistor are connected in series at both ends of the main contactor.

The beneficial effects of the utility model are: the pulse capacitor charging device proposed by the utility model, the battery charging device and the battery discharge device for pulse capacitor charging are completed by the same set of circuits, and the main circuit only needs to switch the switch of the connection switch without complicated The circuit switching can greatly save the time required for the conversion and maintenance of working conditions, and improve the efficiency of the equipment; the cascade structure is used to increase the equivalent switching frequency, thereby greatly reducing the volume and weight of the energy storage inductor, and reducing the overall size of the device. The weight and volume improve the mobility of the system; the rectifier power supply adopts a multiple rectification series structure, which realizes the high voltage, high power quality, high reliability and high efficiency of the rectifier power supply.

Description of drawings

FIG. 1 is a schematic structural diagram of an existing pulse capacitor charging device. Among them, K11-Kn1 is the connection switch of 1# battery module-n# battery modules in series, which is closed when charging the pulse capacitor; Ubs is the output voltage after the battery modules are connected in series, and Uc is the pulse capacitor voltage; The pulse capacitor is charged to its rated value.

Fig. 2 is a schematic structural diagram of a conventional battery charging device. Among them, K11/K12-Kn1/Kn2 is the 1# battery module-n# battery module charging conversion switch, close K11/K12-Kn1/Kn2 in turn, so that the battery charging device is connected with each battery module in turn, and the battery module is completed. Charge.

Fig. 3 is a structural schematic diagram of a high-voltage pulse capacitor charging device proposed by the utility model. The internal structures of the battery, the charging unit and the rectifier power supply are shown in Figure 4 and Figure 6 respectively; K1 is the connection switch between the charging device and the pulse capacitor, which is closed only when the charging device is charging the pulse capacitor, and K1 is disconnected at other times.

FIG. 4 is a schematic diagram of the internal structure of the battery and the charging unit. Among them, L1 is the energy storage inductor, and the structure of 1# battery and charging module—n# battery and charging module is shown in Figure 5.

Fig. 5 is a circuit realization form of a battery and a charging module. Among them, Cd is a filter capacitor; T1 and T2 are power switching devices, the common device IGBT shown in the figure; D1 (D2) is an anti-parallel diode with T1 (T2); T1, T2 and D1, D2 constitute a bidirectional DC/DC module for charging and discharging the battery module.

Figure 6 is a circuit implementation form of the rectified power supply. Among them, QF1 is the input circuit breaker; KM1 is the input main contactor, KM2 is the auxiliary contactor; Rc is the series surge suppression resistor; TR is the rectifier transformer, which outputs four three-phase winding voltages with a phase angle difference of 15°; B1 —B4 is four three-phase rectifier bridges, the structure of which is shown in Figure 7; Udr is the output DC voltage of the rectifier power supply.

FIG. 7 is a schematic structural diagram of a three-phase rectifier bridge structure. Among them, D1-D6 are rectifier diodes; the rectifier bridge converts three-phase AC into 6-pulse DC, and B1-B4 are connected in series to form 24-pulse DC output.

Fig. 8 is a schematic structural diagram of an output DC5500V rectified power supply in the embodiment. Among them, the input voltage is three-phase AC380V alternating current; QF1 is the input circuit breaker; KM1 is the input main contactor, KM2 is the auxiliary contactor; Rc is the series surge suppression resistor; TR is the rectifier transformer, TR output secondary 4 groups of three The phase windings have a difference of 15 degrees in sequence; B1-B4 are four three-phase rectifier bridges, and the structure of the three-phase rectifier bridge is shown in Figure 7; B1-B4 are connected in series to output a DC voltage of DC5500V.

Fig. 9 is a schematic diagram of the structure of a charging device composed of 10 batteries and a charging module given in the embodiment. Among them, 1# battery and charging module-10# battery and charging module have a total of 10 batteries and charging modules, the voltage of the battery module is 600V-1000V; the rated voltage of the pulse capacitor is DC5500V, which is connected to the charging device through the connection switch K1; The structure of the power supply is shown in Figure 8.

Detailed ways

The technical solution of the present utility model will be further described below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figure 3, the high-voltage pulse capacitor charging device proposed by the present invention includes a battery, a charging unit, a rectifying power supply and a connection switch K1. For ease of understanding, the pulse capacitance is also drawn in Figure 3, which is represented by a dotted line box. Wherein the connection switch K1 is used to connect the charging device and the pulse capacitor proposed by the utility model, and is only closed when charging the pulse capacitor, and is in an off state at other times. The structure and principle of the battery, the charging unit and the rectified power supply are introduced below.

The structure of the battery and charging unit is shown in Figure 4, including 1# battery and charging module in series—n# battery and charging module, a total of n batteries and charging modules, and an energy storage inductor L1 connected in series with the 1# battery and charging module. Each battery and charging module includes a battery module and a bidirectional DC/DC module connected in parallel with it. As shown in Figure 5, a specific implementation structure of the battery and charging module is given. In this embodiment, the power switching device adopts an IGBT tube. , the bidirectional DC/DC module consists of a DC side support capacitor Cd, a first power switch tube T1, a second power switch tube T2, a first diode D1 connected in antiparallel with the first power switch tube T1, and a second power switch tube T2 is composed of a second diode D2 connected in antiparallel, and Ub in the figure is the battery voltage.

The n batteries and the bidirectional DC/DC module in the charging module and the energy storage inductor L1 form a cascaded bidirectional DC/DC, which can realize charging and discharging of the battery. The bidirectional DC/DC module in the battery and charging module controls the carrier phase shift by 180°/n, so that the switches of the cascaded bidirectional DC/DC modules are staggered, so that the output current ripple of the energy storage inductor L1 is small, and the cascaded bidirectional DC/DC The DC level switching frequency is n times the switching frequency of a single bidirectional DC/DC module, which can greatly reduce the inductance, volume, weight and noise of the energy storage inductor L1; adjust the duty cycle of each bidirectional DC/DC module pulse, The charging and discharging power of the battery in the module can be adjusted to realize energy control of each module.

The rectified power supply is used to provide power for charging the battery, and one implementation form of the rectified power supply is shown in FIG. 6 . The external AC power supply (which can come from the public power grid or the generator car) is supplied to the transformer TR through the circuit breaker QF1 and the main contactor KM1. The secondary side of the transformer TR has four three-phase windings with a phase angle difference of 15°, each three The phase windings are respectively rectified by four three-phase rectifiers B1, B2, B3, and B4, and then output several thousand volts of DC voltage Udr in series, which is used as a power supply for battery charging. As shown in Figure 7, it is a realization circuit of three-phase rectification. In some embodiments, an auxiliary contactor KM2 and a series surge suppression resistor Rc can also be set in the rectified power supply to suppress the surge current caused by magnetic flux saturation when the transformer is switched on. Before the main contactor KM1 is closed, the auxiliary contactor is closed first. The device KM2 and the surge suppression resistor Rc in series can suppress the closing surge current of the transformer TR and reduce the impact on the AC power supply. B1-B4 form a 24-pulse rectifier so that the output voltage Udr of the DC side has very small ripples, and at the same time, the side of the AC power supply has a high power factor and an extremely low current distortion rate. In addition, the main components of rectified power conversion are only transformers and rectifier diodes, without the participation of active devices and controls, so it has high efficiency and high reliability. It is worth noting that the rectifier power supply is used to convert alternating current into high-voltage direct current, and then supply power to the battery through cascaded bidirectional DC/DC. The rectifier power supply of other structures is also applicable to the utility model. The number of pulses can be changed, such as 12 pulses, 18 pulses, etc.

The operating principle and working process of the present embodiment are:

1) Battery charging

Before charging the pulse capacitor, the battery needs to be charged with a small power to store the energy. When charging the battery, the connection switch K1 is disconnected, the circuit breaker QF1 of the rectified power supply is closed, the auxiliary contactor KM2 is closed first, and then the main contactor KM1 is closed, and the rectified power supply outputs a DC voltage Udr to supply power to the battery and charging unit. The cascaded bidirectional DC/DC formed by the bidirectional DC/DC module in the battery and charging unit and the energy storage inductor L1 works in boost (boost) mode, and transmits the energy output by the AC grid through the rectified power supply to each battery module. The charging process stops until the battery is fully charged, and the charging power can be limited according to the capacity of the AC power supply.

2) Pulse capacitor charging

Charging the pulse capacitor is required to be completed within a few seconds, and the power is at the MW level. Charge the pulse capacitor, that is, discharge the battery to the pulse capacitor. At this time, the connection switch K1 is closed, the main contactor KM1 and the circuit breaker QF1 of the AC side of the rectified power supply are disconnected, and there is no DC voltage output (Udr=0V). The battery and the charging unit are bidirectional The cascaded bidirectional DC/DC formed by the DC/DC module and the energy storage inductor L1 works in the busk (step-down) mode, and transmits energy from the battery to the pulse capacitor. The pulse capacitor voltage Uc rises from 0V to the rated voltage and stops charging. After the charging of the pulse capacitor is completed, the pulse capacitor is controlled by the switch to discharge the electromagnetic propulsion device to complete a propulsion launch. After one push is completed, the pulse capacitor voltage drops to 0, and the previous charging process can be repeated to charge the capacitor again. Carry out multiple charging and propulsion continuously until the stored energy of the battery is exhausted, and the battery is recharged.

It should be noted that: when charging the battery, the cascaded bidirectional DC/DC works in boost mode, and the sum nUb of the voltages of all battery modules should be greater than the output voltage Udr of the rectified power supply; when charging the pulse capacitor, that is, when the battery is discharged, the cascaded bidirectional DC/DC works in buck mode, and the sum nUb of the voltages of the electrical modules should be greater than the rated voltage of the pulse capacitor. Voltage matching to be considered in device design.

When the charging device of the present utility model is applied in actual engineering, the power supply for charging the battery can be AC voltage or DC voltage, whether it is AC voltage or DC voltage, charging the battery and charging the pulse capacitor (battery discharge) ) The two working conditions of the device are implemented by switching between two working modes of the same main circuit, without complex switch conversion. If the external power grid is a DC power supply, the DC power supply is converted into a high-voltage DC power of the required voltage level through a DC-DC converter or a DC-AC-DC converter.

The following uses the most commonly used three-phase AC AC380V external power supply, and the pulse capacitor charging device with a pulse capacitor rated voltage of DC5500V as an example to illustrate the specific implementation.

The rectified power supply provides power for charging the battery. Figure 8 is a structural diagram of a rectified power supply with an input three-phase AC AC380V and an output DC voltage of DC5500V. When the rectifier power supply is working, the circuit breaker QF1 is closed, the auxiliary contactor KM2 is closed first, and the surge suppression resistor Rc is connected in series. After a delay of several seconds, the main contactor KM1 is closed, and the surge suppression resistor Rc is cut off. The AC voltage is supplied to the transformer TR, and the four three-phase windings on the secondary side of the transformer are respectively rectified by the rectifier bridge B1-B4 and then connected in series, and the output is DC5500V DC voltage as the power supply for battery charging. The phase difference between the four secondary three-phase windings of the rectifier transformer TR is 15°, and the output DC voltage of the rectifier is 24 pulses. Not only the output voltage ripple is small, but also the AC input side has a high power factor and extremely low current distortion rate; at the same time, the rectified power supply The main power components are only transformers and rectifier diodes, so the rectifier power supply has high reliability and high efficiency.

Fig. 9 is a structural diagram of a charging device composed of 10 batteries and a charging module. In Figure 9, the voltage of each battery module is DC600V-1000V, and the sum of the voltages of 10 modules is DC6000V-10000V; 10 bidirectional DC/DC modules are connected in series and form a 10-level cascaded bidirectional DC/DC with energy storage inductor L1. When the battery is charging, the connection switch K1 is disconnected, the circuit breaker QF1 and the main contactor KM1 are closed in Figure 8, the output voltage is DC5500V, the cascaded bidirectional DC/DC works in boost mode, and the output energy of the DC5500V DC power supply is delivered to the storage battery. Charge until each battery module reaches DC1000V. In order to reduce the capacity of the external power supply, the power to charge the battery is relatively small, and it takes a long time to complete. When the battery is discharged and the pulse capacitor is charged, the connection switch K1 is closed, the main contactor KM1 and auxiliary contactor KM2 of the rectifier power supply are disconnected, the output voltage of the rectifier power supply is 0V, and the cascaded bidirectional DC/DC works in buck mode, with MW-level power Charge the pulse capacitor and deliver the battery energy to the pulse capacitor. The charging process makes the voltage of the pulse capacitor rise from 0V to the rated DC5500V voltage in a few seconds. After charging is complete, switch K1 is disconnected. Then the pulse capacitor can be controlled by the switch to discharge the propulsion system, the pulse capacitor releases the stored energy in a very short time, and the capacitor voltage drops to 0V. The energy stored in the battery can be used for multiple propulsion drives. Therefore, the above-mentioned charging and discharging process of the pulse capacitor can be performed continuously for many times, and multiple propulsion launches can be completed in a short time.

In the above device, if the operating switching frequency of the switch is 2kHz, and the switching frequency of the 10-level cascaded bar is 20kHz, the inductance of the energy storage sense L1 is very small, and because the current pulse frequency is 20kHz, there will be no hearing loss. Noise heard.

In practical applications, in order to improve reliability, multiple batteries and charging units can be connected in parallel to implement a large-capacity charging device.

To sum up, the charging device proposed by the utility model realizes the charging device of the energy storage battery and the discharging device of the pulse capacitor by the same circuit and control system, and the two working conditions do not need complicated switching, and only need to control the connection switch K1 One switch saves the time required for working condition conversion and maintenance, and improves equipment efficiency; adopts a cascaded structure to increase the equivalent switching frequency, thereby greatly reducing the volume and weight of the energy storage inductor, thereby reducing the overall weight of the device and volume, which improves the mobility of the system; the rectifier power supply adopts a multiple rectification series structure, which realizes high voltage, high power quality, high reliability and high efficiency of the rectifier power supply. Applying the utility model to electromagnetic propulsion places such as electromagnetic guns can reduce the preparation time, reduce the volume and weight of the device, and improve the mobility of the system.

The above content has carried out a detailed introduction to the utility model, and the application of specific examples of the utility model has explained the principle and implementation mode of the utility model, and the above examples are only used to help understand the basic principles and core ideas of the utility model , changes made to specific implementation methods based on the basic principles and core ideas of the utility model should all fall within the scope of the utility model.

Claims (4)

1. A high-voltage pulse capacitor charging device is characterized by comprising a battery, a charging unit, a rectifying power supply and a connecting switch,

The battery and charging unit comprises an energy storage inductor, n batteries and a charging module which are sequentially connected in series, two ends of the series structure are connected with the output voltage of the rectification power supply, wherein n is a positive integer; the battery and charging modules comprise battery modules and bidirectional DC/DC modules which are connected in parallel, and the bidirectional DC/DC modules in the n battery and charging modules and the energy storage inductor form cascaded bidirectional DC/DC;

The voltage at the two ends of the battery and charging unit is controlled by the connecting switch to be applied to the two ends of the pulse capacitor, when the connecting switch is disconnected, the cascade bidirectional DC/DC controls the rectifying power supply to charge the battery modules in the n batteries and charging modules, and when the connecting switch is closed, the cascade bidirectional DC/DC controls the battery modules in the n batteries and charging modules to charge the pulse capacitor.

2. the high voltage pulse capacitor charging device according to claim 1, wherein the bidirectional DC/DC module in the ith battery and charging module comprises a DC-side supporting capacitor, a first power switch device, a second power switch device, a first diode connected in anti-parallel with the first power switch device, and a second diode connected in anti-parallel with the second power switch device, one end of the first power switch device is connected to one end of the DC-side supporting capacitor and one end of the battery module in the ith battery and charging module, and the other end of the first power switch device is connected to one end of the second power switch device; the other end of the second power switch device is connected with the other end of the direct-current side supporting capacitor and the other end of a battery module in the ith battery and charging module; two ends of the second power switch device are respectively used as the input end and the input end of the ith battery and charging module to be connected with the output end of the (i-1) th battery and charging module and the input end of the (i + 1) th battery and charging module, and i belongs to [2, n-1 ]; the input end of the 1 st battery and charging module is connected with one end of the rectification power supply after passing through the energy storage inductor, and the output end of the nth battery and charging module is connected with the other end of the rectification power supply.

3. The high-voltage pulse capacitor charging device according to claim 1 or 2, wherein the rectifying power supply comprises a circuit breaker, a main contactor, a transformer and four three-phase rectifiers, one end of the circuit breaker is connected with an external alternating current power supply, and the other end of the circuit breaker is connected with a primary winding of the transformer after passing through the main contactor; the secondary of the transformer comprises four three-phase windings with phase angles sequentially different by 15 degrees, and the four three-phase windings are respectively output in series by voltages rectified by four three-phase rectifiers and serve as output voltages of the rectification power supply.

4. The high voltage pulse capacitor charging apparatus according to claim 3, wherein the rectified power supply further comprises an auxiliary contactor and a series surge suppression resistor, the auxiliary contactor and the series surge suppression resistor being connected in series and in parallel across the main contactor.