Control apparatus for boost converter
A control apparatus for the boost converter to reduce the total loss is proposed. The control apparatus for the boost converter which controls the boost converter in a power system, the system has a DC power source having source voltage; the boost converter including a switching device and boosting the source voltage by predetermined boost control including change of switching state of the switching device based on boost instruction voltage and outputs the boosted voltage to a load apparatus; and a voltage detecting device detecting output voltage of the boost converter, the control apparatus has: a boost controlling device performing the boost control; and an intermittent controlling device performing intermittent process of the boost control based on the detected output voltage to keep the output voltage within range including the boost instruction voltage which is used when the last boost control is performed.
1. A control apparatus for a boost converter which controls the boost converter in an electrical power supply system, the electrical power supply system comprising:
a DC (Direct Current) electrical power source having a source voltage;
the boost converter which includes a switching device and configured to boost the source voltage and output the boosted source voltage to a load apparatus by a predetermined boost control including switching of a switching state of the switching device based on a boost instruction voltage; and
a voltage sensor configured to detect an output voltage of the boost converter,
the control apparatus comprising:
a boost controlling unit configured to execute the boost control; and
an intermittent controlling device configured to execute repeatedly an intermittent process of the boost control based on the detected output voltage to keep the output voltage within a range including the boost instruction voltage which is set in an immediately preceding execution of the boost control, wherein
the intermittent controlling device starts the intermittent process of the boost control when the output voltage reaches the boost instruction voltage; and
the intermittent controlling device stops the intermittent process of the boost control when the output voltage reaches a lower or a higher limiting value of a predetermined range of the boost instruction voltage.
2. The control apparatus for the boost converter according to claim 1 , wherein the control apparatus further comprises a setting device configured to set the range on the basis of at least one of the source voltage, a withstand voltage of the boost converter, the boost instruction voltage and a loss generated when the load apparatus is driven.
3. The control apparatus for the boost converter according to claim 1 , wherein the intermittent controlling device resumes the boost control when the output voltage exceeds a boundary value of the range in executing the intermittent process of the boost control.
4. The control apparatus for the boost converter according to claim 1 , wherein the boost controlling unit varies the output voltage between the boost instruction voltage and the boundary value of the range in executing the intermittent process of the boost control.
5. The control apparatus for the boost converter according to claim 1 , wherein
the electrical power supply system further comprises a current sensor which detects a current flowing in the boost converter or the DC electrical power source,
the intermittent controlling device starts the intermittent process of the boost control when the detected current is within a predetermined value.
6. The control apparatus for the boost converter according to claim 1 , wherein the control apparatus further comprises an output change specifying unit which specifies a degree of a variation of an output of the DC electrical power source or the load apparatus,
the intermittent controlling device starts the intermittent process of the boost control when the degree of the variation of the output of the DC electrical power source or the load apparatus is within a predetermined value.
7. The control apparatus for the boost converter according to claim 1 , wherein the electrical power supply system is mounted on a vehicle.
8. The control apparatus for the boost converter according to claim 7 , wherein the vehicle comprising at least one rotating electrical machine, as a driving power source of the vehicle, which is the load apparatus and which is capable of performing a power-running and a regeneration.
9. A control apparatus for a boost converter which controls the boost converter in an electrical power supply system,
the electrical power supply system comprising:
a DC (Direct Current) electrical power source having a source voltage;
the boost converter which includes a switching device and configured to boost the source voltage and output the boosted source voltage to a load apparatus by a predetermined boost control including switching of a switching state of the switching device based on a boost instruction voltage; and
a voltage sensor configured to detect an output voltage of the boost converter,
the control apparatus comprising:
a boost controlling unit configured to execute the boost control; and
an intermittent controlling device configured to execute repeatedly an intermittent process of the boost control based on the detected output voltage to keep the output voltage within a range including the boost instruction voltage which is set in an immediately preceding execution of the boost control, wherein
the electrical power supply system is mounted on a vehicle;
the vehicle is a hybrid vehicle which comprises:
an engine;
a first rotating electrical machine which is the load apparatus and which is capable of performing a power-running and a regeneration;
a differential mechanism comprising a plurality of rotating elements, the plurality of rotating elements are capable of differentially rotating and include a first rotating element which is connected to the first rotating electrical machine, a second rotating element which is connected to the engine and a third rotating element which is connected to a driving shaft being connected to an axle shaft; and
a second rotating electrical machine which is connected to the driving shaft, which is the load apparatus and which is capable of performing a power-running and a regeneration,
the controller is configured to start the intermittent process of the boost control when a difference between an input and output of the electrical power of the first and second rotating electrical machines is within a predetermined value in the case where one of the first and second rotating electrical machines is in a power-running state and the other one of the first and second rotating electrical machines is in a regeneration state.
10. The control apparatus for the boost converter according to claim 9 , wherein the controller is further configured to control the first and second rotating electrical machines and the engine to balance the input and output of the electrical power, when the start of the intermittent process of the boost control is subject to the difference between the input and output of the electrical power being within the predetermine value.
11. The control apparatus for the boost converter according to claim 10 , wherein the controller is configured to change an operation point of the engine by changing a rotational number of the first rotating electrical machine in balancing the input and output of the electrical power.
12. The control apparatus for the boost converter according to claim 11 , wherein the controller is configured to change the operation point of the engine under such a condition that a reduction amount of a loss due to the intermittent process of the boost control exceeds an increasing amount of a loss due to the change of the operation point of the engine.