CN204424865U - Power distribution equipment - Google Patents

Abstract

The utility model provides a power distribution device, which is used for distributing power to loads electrically connected to a positive DC bus and a negative DC bus through a switch. The power distribution device includes: a voltage sampling device for converting the power supply voltage between the positive DC bus and the negative DC bus into a corresponding voltage sampling signal; a current sampling device for converting the power supply provided to the load The current is converted into a corresponding current sampling signal; the control signal output device is used to output a switch control signal according to the received voltage sampling signal and current sampling signal; and the switch control device is used to control the switch according to the switch control signal status. The power distribution device of the utility model can quickly and accurately distribute power to loads, and has high safety and reliability.

Description

Power distribution device

technical field

The utility model relates to the field of power electronics, in particular to a power distribution device.

Background technique

As a zero-emission motor vehicle, electric vehicles will have a long-term market prospect. In order to make electric vehicles reach the level of fuel vehicles in terms of comfort and operability, a series of power consumption equipment (loads) need to be added. Such as electric brakes, air conditioners, defrosters, DC/AC inverters and DC/DC converters, etc.

Since the electric power of the battery pack in the electric vehicle is limited, it is necessary to distribute the electric energy of the battery pack in order to efficiently utilize the electric energy of the battery pack during the running of the electric vehicle. A power distribution scheme in the prior art is to connect a fuse corresponding to the rated power of the load between the load and the positive DC bus. When the power consumed by the load exceeds the rated power, the load has a short circuit or other faults, the fuse Burning to cut off the power supply to the load, the power distribution scheme has a single function. Another power distribution scheme in the prior art is to measure the voltage and current on the load to judge whether to supply power to the load or to cut off the power. It is easy to cause safety hazards in the process.

Utility model content

In view of the above problems, an embodiment of the present invention provides a power distribution device, which is used to distribute power to loads electrically connected to the positive DC bus and the negative DC bus through switches, and the power distribution device include:

A voltage sampling device, configured to convert the power supply voltage between the positive DC bus and the negative DC bus into corresponding voltage sampling signals;

a current sampling device, configured to convert the supply current provided to the load into a corresponding current sampling signal;

a control signal output device, configured to output a switch control signal according to the received voltage sampling signal and current sampling signal; and

The switch control device is used for controlling the state of the switch according to the switch control signal.

Preferably, the control signal output device includes:

A load detection device, configured to compare the current sampling signal with a predetermined current threshold, output a first fault signal when the current sampling signal is greater than the predetermined current threshold, and output a first fault signal when the current sampling signal is not greater than the Outputting a first normal signal at a predetermined current threshold;

A power detection device, configured to acquire the power of the load according to the voltage sampling signal and the current sampling signal, output a second fault signal when the power of the load is greater than a predetermined power threshold, and output a second fault signal when the power of the load is not greater than the predetermined power threshold outputting a second normal signal when the predetermined power threshold is reached; and

A fault processing device, the input end of the fault processing device is connected to the output end of the load detection device and the power detection device, and when any one of the first fault signal and the second fault signal is received, a switch shutdown signal is output , outputting a switch conduction signal when receiving the first normal signal and the second normal signal.

Preferably, the voltage sampling device includes:

a voltage measuring device, the input terminal of the voltage measuring device is electrically connected to the positive DC bus and the negative DC bus, and is used to output an analog voltage signal corresponding to the power supply voltage, and the amplitude of the analog voltage signal is smaller than the the magnitude of the supply voltage;

The analog voltage signal adjustment circuit is used to convert the received analog voltage signal into a voltage sampling signal.

Preferably, the voltage sampling device further includes a voltage filter circuit electrically connected between the voltage measurement device and the analog voltage signal adjustment circuit, for filtering high-frequency noise in the analog voltage signal.

Preferably, the current sampling device includes:

current measuring means for converting the supply current into an analog current signal having a magnitude smaller than the magnitude of the supply current; and

The analog current signal adjustment circuit is used to convert the received analog current signal into a current sampling signal.

Preferably, the current sampling device further includes a current filter circuit electrically connected between the current measurement device and the analog current signal adjustment circuit, for filtering high-frequency noise in the analog current signal.

Preferably, the power distribution device further includes:

a switch state measuring device for measuring the state of the switch and outputting a switch state signal; and

The switch fault detection device is used for receiving and comparing the switch state signal and the switch control signal, and outputting a switch fault signal when the switch state signal is inconsistent with the switch control signal.

Preferably, the power distribution device further includes an arc detection device for judging the arc intensity between the positive DC bus and the negative DC bus based on an arc diagnosis algorithm, and outputting an arc intensity signal corresponding to the arc intensity to The fault processing device, when the fault processing device receives the first normal signal, the second normal signal, and the arc intensity signal is less than a predetermined arc intensity threshold, it outputs a switch conduction signal, otherwise the fault processing device outputs Switch off signal.

Preferably, the power distribution device further includes a signal transmission device for controlling the state of the switch according to the received external control signal.

Preferably, the power distribution device further includes a charging switch, a current limiting device, a capacitor, a first discharge switch, and a second discharge switch, one end of the first discharge switch is electrically connected to one end of the second discharge switch to form a node, and the The other end of the first discharge switch is electrically connected to the positive stage of the capacitor, the other end of the second discharge switch is electrically connected to the negative electrode of the capacitor and the negative DC bus, the charging switch and the current limiting The device is connected in series between the node and the positive pole of the capacitor.

The power distribution device of the utility model can realize fast power distribution to loads, and the power distribution device will not bring safety hazards.

Description of drawings

The utility model embodiment is described further below with reference to accompanying drawing, wherein:

Fig. 1 is a circuit diagram of a power distribution device in a preferred embodiment of the present invention.

Detailed ways

In order to make the purpose, technical solutions and advantages of the utility model clearer, the utility model will be further described in detail through specific embodiments in conjunction with the accompanying drawings.

Fig. 1 is a circuit diagram of a power distribution device in a preferred embodiment of the present invention. As shown in FIG. 1 , the power distribution device 100 includes a voltage sampling device 20 , a current sampling device 30 , a control signal output device 40 , a switch control device 50 , a switch state measurement device 61 , a switch fault detection device 62 , and a pre-charging and discharging device 70 . The load 80 is electrically connected to the positive DC bus 11 and the negative DC bus 12 through the pre-charging and discharging device 70 and the switch S1.

The voltage sampling device 20 includes a voltage measuring device 21 , a voltage filter circuit 22 and an analog voltage signal adjustment circuit 23 . The input end of the voltage measuring device 21 is connected to the positive DC bus 11 and the negative DC bus 12 for measuring the supply voltage between the positive DC bus 11 and the negative DC bus 12 and outputting an analog voltage signal corresponding to the supply voltage. Wherein the amplitude of the analog voltage signal is less than or much smaller than the amplitude of the power supply voltage, for example, the amplitude of the analog voltage signal is less than 12 volts, so that the entire power distribution device will not cause electric shock to the human body and avoid high-voltage electric shocks. coming security risks. The input terminal of the voltage filter circuit 22 is electrically connected to the output terminal of the voltage measuring device 21, and is used to filter the noise in the received analog voltage signal. Those skilled in the art know that the frequency of the noise in the analog voltage signal is usually higher , so the low-pass filter can be selected to filter the high-frequency noise in the analog voltage signal. The input terminal of the analog voltage signal adjustment circuit 23 is electrically connected to the output terminal of the voltage filter circuit 22 for converting the analog voltage signal from which high-frequency noise has been filtered into a corresponding voltage sampling signal and providing it to the control signal output device 40 . According to the voltage amplitude that the control signal output device 40 can receive, the voltage sampling signal can be, for example, a voltage value between 0-3 volts or 1-5 volts.

The current sampling device 30 includes a current measuring device 31 , a current filter circuit 32 and an analog current signal adjustment circuit 33 . The current measuring device 31 is used to measure the supply current in the wire between the positive DC bus 11 and an input end of the load 80 , and output an analog current signal corresponding to the supply current. Wherein the amplitude of the analog current signal is smaller than the amplitude of the supply current. The input terminal of the current filter circuit 32 is electrically connected to the output terminal of the current measuring device 31, and is used to filter the noise in the received analog current signal. According to the frequency range of the actual current noise, a low-pass filter can also be selected to filter the analog current signal. Filter high frequency noise in the signal. The input terminal of the analog current signal adjustment circuit 33 is electrically connected to the output terminal of the current filter circuit 32 for converting the analog current signal from which high-frequency noise is filtered into a corresponding current sampling signal and providing it to the control signal output device 40 . According to the magnitude of the current that the control signal output device 40 can receive, the current sampling signal can be, for example, a current value between 0-20 mA.

The control signal output device 40 includes an arc detection device 41 , a load detection device 42 , a power measurement device 43 and a fault processing device 44 .

The arc detection device 41 receives the voltage sampling signal and the current sampling signal, and based on an arc diagnosis algorithm, such as an arc fault pattern recognition algorithm, judges whether there is an arc between the positive DC bus 11 and the negative DC bus 12 and the intensity of the arc, and outputs a The analog or digital signal corresponding to the intensity.

The load detection device 42 receives the current sampling signal, compares the current sampling signal with a predetermined current threshold, and outputs a load fault signal if the current sampling signal is greater than the predetermined current threshold. Outputting a load normal signal when the current sampling signal is not greater than a predetermined current threshold. Those skilled in the art know that the load fault signal and the load normal signal can be analog or digital. For example, "0" can be used to represent the load fault signal, and "1" can be used to represent the load normal signal.

The power measuring device 43 receives the voltage sampling signal and the current sampling signal, and obtains the power of the load. When the power of the load is greater than a predetermined power threshold, a power fault signal is output, and when the power of the load is not greater than a predetermined power threshold, a power normal signal is output. Those skilled in the art know that the power failure signal and the power normal signal can be analog or digital. For example, "0" may be used to indicate a power failure signal, and "1" may be used to indicate a power normal signal.

The fault processing device 44 receives the arc intensity signal output by the arc detection device 41 , the load fault signal or load normal signal output by the load detection device 42 , and the power fault signal or power normal signal output by the power measurement device 43 . When the value of the arc intensity signal received by the fault processing device 44 is less than a predetermined arc intensity threshold, and the load normal signal and the power normal signal are received, the switch-on signal is output. Otherwise, output switch off signal.

The switch control device 50 receives the switch control signal output by the fault processing device 44 and controls the state of the switch S1 based on the switch control signal. For example, receiving the switch-on signal controls the switch S1 to turn on; receiving the switch-off signal controls the switch S1 to turn off.

The switch state detection device 61 is used to detect the switch state of the switch S1 (ie, on or off), and send the switch state signal of the switch S1 to the switch failure detection device 62 . The switch state of the switch S1 can be detected in various ways, for example, the switch state of the switch S1 can be detected according to the voltage and current of the switch S1, or the contact distance of the switch.

The switch fault detecting device 62 receives the switch state signal output by the switch state measuring device 61 and the switch control signal sent by the fault processing device 44, and judges whether the switch S1 is faulty. If the switch control signal output by the fault processing device 44 is consistent with the switch state signal of the switch S1, it is detected that the switch S1 is not faulty, otherwise it is determined that the switch S1 is faulty. Through the self-detection of the function of the switch S1 by the switch state detection device 61 and the switch fault detection device 62 , the safe power distribution of the power distribution device 100 can be ensured, and the safety of power consumption can be improved.

The pre-charging and discharging device 70 electrically connected between the switch S1 and the load 80 includes switches S2, S3, S4, a resistor R, an inductor L and a capacitor C. The switches S2 and S3 are connected to form a node N1, the other end of the switch S2 is connected to the positive pole of the capacitor C, and the other end of the switch S3 is connected to the negative pole of the capacitor C and the negative DC bus 12, so that the switches S2, S3 and the capacitor C form a discharge circuit. The switch S4, the resistor R and the inductor L are sequentially connected in series and connected between the node N1 and the positive pole of the capacitor C, thereby forming a pre-charging circuit with the capacitor C. During the precharging process, the switch S1 is turned on, the switches S2 and S3 are turned off, and the switch S4 is turned on, so that the capacitor C is precharged. When the load 80 stops working, the switch S1 is turned off, the switch S4 is turned off, and the switches S2 and S3 are turned on, so as to discharge the capacitor C. By precharging the capacitor C, damage to the load 80 can be avoided. When the power supply to the load is stopped, by discharging the capacitor C, the remaining power on the capacitive load can cause accidental electric shock.

The power distribution device of the present utility model adopts the voltage sampling device 20 and the current sampling device 30 to avoid potential safety hazards caused by the high voltage control process. Using the control signal output device 40 can quickly and accurately control the state of the switch S1. In addition, the power distribution device 100 also has a fault self-detection function of the switch S1, which further improves safety and reliability. The pre-charging and discharging device 70 protects the load and the risk of accidental electric shock.

In other embodiments of the present invention, the power distribution device 100 further includes a signal transmission device, configured to receive an external control signal, and control the switch state of the switch S1 according to the external control signal. The external control signal can be provided to the signal transmission device in various ways. The external control signal mentioned here refers to a switch control signal that is different from the switch control signal generated or output by the power distribution device 100 .

In other embodiments of this method, other current limiting devices can be used instead of the resistor R and the inductor L. The switches S2, S3 and S4 in the precharging and discharging device 70 may be relays or various switching transistors.

In other embodiments of the present invention, there may be no pre-charging and discharging device 70 .

In other embodiments of the present invention, when the voltages of the positive DC bus 11 and the negative DC bus 12 have no or only a small amount of high-frequency noise components, the voltage filter circuit 22 may not be provided. Wherein, the analog voltage signal adjustment circuit 23 converts the analog voltage signal output by the voltage measuring device 21 into a voltage sampling signal.

In other embodiments of the present invention, the current filter circuit 32 may not be provided, wherein the analog current signal adjustment circuit 33 converts the analog current signal output by the current measuring device 31 into a current sampling signal.

In other embodiments of the present invention, the switch state measurement device 61 and the switch fault detection device 62 may not be provided.

It should be understood that the analog voltage signal adjustment circuit 23, the analog current signal adjustment circuit 33, the arc detection device 41, the load detection device 42, the power detection device 43, the fault processing device 44, and the switch state measurement device in the power distribution device of the present utility model Both 61 and the switch fault detection device 62 can be implemented in the hardware form of Field Programmable Gate Array (FPGA) or Application Specific Integrated Circuit (ASIC).

Although the present invention has been described through preferred embodiments, the present invention is not limited to the embodiments described here, and various changes and changes are included without departing from the scope of the present invention.

Claims (10)

1. A power distribution device, the power distribution device is used to distribute power to loads electrically connected to the positive DC bus and the negative DC bus through switches, characterized in that the power distribution device includes: A voltage sampling device, configured to convert the power supply voltage between the positive DC bus and the negative DC bus into corresponding voltage sampling signals; a current sampling device, configured to convert the supply current provided to the load into a corresponding current sampling signal; a control signal output device, configured to output a switch control signal according to the received voltage sampling signal and current sampling signal; and The switch control device is used for controlling the state of the switch according to the switch control signal. 2. The power distribution device according to claim 1, wherein the control signal output device comprises: A load detection device, configured to compare the current sampling signal with a predetermined current threshold, output a first fault signal when the current sampling signal is greater than the predetermined current threshold, and output a first fault signal when the current sampling signal is not greater than the Outputting a first normal signal at a predetermined current threshold; A power detection device, configured to acquire the power of the load according to the voltage sampling signal and the current sampling signal, output a second fault signal when the power of the load is greater than a predetermined power threshold, and output a second fault signal when the power of the load is not greater than the predetermined power threshold outputting a second normal signal when the predetermined power threshold is reached; and A fault processing device, the input end of the fault processing device is connected to the output end of the load detection device and the power detection device, and when any one of the first fault signal and the second fault signal is received, a switch shutdown signal is output , outputting a switch conduction signal when receiving the first normal signal and the second normal signal. 3. The power distribution device according to claim 1, wherein the voltage sampling device comprises: a voltage measuring device, the input terminal of the voltage measuring device is electrically connected to the positive DC bus and the negative DC bus, and is used to output an analog voltage signal corresponding to the power supply voltage, and the amplitude of the analog voltage signal is smaller than the the magnitude of the supply voltage; The analog voltage signal adjustment circuit is used to convert the received analog voltage signal into a voltage sampling signal. 4. The power distribution device according to claim 3, wherein the voltage sampling device further comprises a voltage filter circuit electrically connected between the voltage measurement device and the analog voltage signal adjustment circuit, for filtering the high frequency noise in the analog voltage signal described above. 5. The power distribution device according to claim 1, wherein the current sampling device comprises: current measuring means for converting the supply current into an analog current signal having a magnitude smaller than the magnitude of the supply current; and The analog current signal adjustment circuit is used to convert the received analog current signal into a current sampling signal. 6. The power distribution device according to claim 5, wherein the current sampling device further comprises a current filter circuit electrically connected between the current measurement device and the analog current signal adjustment circuit, for filtering the High frequency noise in analog current signals. 7. The power distribution device according to any one of claims 1 to 6, wherein the power distribution device further comprises: a switch state measuring device for measuring the state of the switch and outputting a switch state signal; and The switch fault detection device is used for receiving and comparing the switch state signal and the switch control signal, and outputting a switch fault signal when the switch state signal is inconsistent with the switch control signal. 8. The power distribution device according to claim 2, wherein the power distribution device further comprises an arc detection device for judging the arc intensity between the positive DC bus and the negative DC bus based on an arc diagnosis algorithm, And output the arc intensity signal corresponding to the arc intensity to the fault processing device, the fault processing device receives the first normal signal, the second normal signal, and the arc intensity signal is less than a predetermined arc intensity threshold output a switch-on signal; otherwise, the fault processing device outputs a switch-off signal. 9. The power distribution device according to any one of claims 1 to 6, characterized in that the power distribution device further comprises a signal transmission device for controlling the state of the switch according to a received external control signal. 10. The power distribution device according to any one of claims 1 to 6, wherein the power distribution device further comprises a charging switch, a current limiting device, a capacitor, a first discharge switch and a second discharge switch, so One end of the first discharge switch is electrically connected to one end of the second discharge switch to form a node, the other end of the first discharge switch is electrically connected to the positive stage of the capacitor, and the other end of the second discharge switch is electrically connected to the The negative pole of the capacitor and the negative DC bus, the charging switch and the current limiting device are connected in series between the node and the positive pole of the capacitor.